diff --git a/apps/acls/managers.py b/apps/acls/managers.py
index 6ba807a897..529643c7ec 100644
--- a/apps/acls/managers.py
+++ b/apps/acls/managers.py
@@ -137,14 +137,14 @@ class AccessEntryManager(models.Manager):
         content_type = ContentType.objects.get_for_model(cls)
 
         # Calculate actor role membership ACL query
-        total_queries = None
+        total_queries = Q()
         for role in RoleMember.objects.get_roles_for_member(actor):
             role_type = ContentType.objects.get_for_model(role)
             if related:
                 query = Q(holder_type=role_type, holder_id=role.pk, permission=permission.get_stored_permission)
             else:
                 query = Q(holder_type=role_type, holder_id=role.pk, content_type=content_type, permission=permission.get_stored_permission)
-            if total_queries is None:
+            if not total_queries:
                 total_queries = query
             else:
                 total_queries = total_queries | query
@@ -161,7 +161,7 @@ class AccessEntryManager(models.Manager):
                 query = Q(holder_type=group_type, holder_id=group.pk, permission=permission.get_stored_permission)
             else:
                 query = Q(holder_type=group_type, holder_id=group.pk, content_type=content_type, permission=permission.get_stored_permission)
-            if total_queries is None:
+            if not total_queries:
                 total_queries = query
             else:
                 total_queries = total_queries | query
diff --git a/apps/checkouts/__init__.py b/apps/checkouts/__init__.py
new file mode 100644
index 0000000000..2ad1a215b6
--- /dev/null
+++ b/apps/checkouts/__init__.py
@@ -0,0 +1,47 @@
+from __future__ import absolute_import
+
+from django.utils.translation import ugettext_lazy as _
+
+from navigation.api import (register_links, register_top_menu,
+    register_multi_item_links, register_sidebar_template)
+from scheduler.api import register_interval_job
+
+from documents.models import Document
+from documents.permissions import PERMISSION_DOCUMENT_VIEW
+from acls.api import class_permissions
+from history.api import register_history_type
+
+from .permissions import (PERMISSION_DOCUMENT_CHECKOUT,
+    PERMISSION_DOCUMENT_CHECKIN, PERMISSION_DOCUMENT_CHECKIN_OVERRIDE,
+    PERMISSION_DOCUMENT_RESTRICTIONS_OVERRIDE)
+from .links import checkout_list, checkout_document, checkout_info, checkin_document
+from .models import DocumentCheckout
+from .tasks import task_check_expired_check_outs
+from .events import HISTORY_DOCUMENT_CHECKED_OUT, HISTORY_DOCUMENT_CHECKED_IN
+
+
+def initialize_document_checkout_extra_methods():
+    Document.add_to_class('is_checked_out', lambda document: DocumentCheckout.objects.is_document_checked_out(document))
+    Document.add_to_class('check_in', lambda document, user=None: DocumentCheckout.objects.check_in_document(document, user))
+    Document.add_to_class('checkout_info', lambda document: DocumentCheckout.objects.document_checkout_info(document))
+    Document.add_to_class('checkout_state', lambda document: DocumentCheckout.objects.document_checkout_state(document))
+    Document.add_to_class('is_new_versions_allowed', lambda document, user=None: DocumentCheckout.objects.is_document_new_versions_allowed(document, user))
+
+register_top_menu(name='checkouts', link=checkout_list)
+register_links(Document, [checkout_info], menu_name='form_header')
+register_links(['checkout_info', 'checkout_document', 'checkin_document'], [checkout_document, checkin_document], menu_name="sidebar")
+
+class_permissions(Document, [
+    PERMISSION_DOCUMENT_CHECKOUT,
+    PERMISSION_DOCUMENT_CHECKIN,
+    PERMISSION_DOCUMENT_CHECKIN_OVERRIDE,
+    PERMISSION_DOCUMENT_RESTRICTIONS_OVERRIDE
+])
+
+CHECK_EXPIRED_CHECK_OUTS_INTERVAL=60  # Lowest check out expiration allowed
+register_interval_job('task_check_expired_check_outs', _(u'Check expired check out documents and checks them in.'), task_check_expired_check_outs, seconds=CHECK_EXPIRED_CHECK_OUTS_INTERVAL)
+initialize_document_checkout_extra_methods()
+register_history_type(HISTORY_DOCUMENT_CHECKED_OUT)
+register_history_type(HISTORY_DOCUMENT_CHECKED_IN)
+
+#TODO: forcefull check in
diff --git a/apps/checkouts/events.py b/apps/checkouts/events.py
new file mode 100644
index 0000000000..6d91d8d4ea
--- /dev/null
+++ b/apps/checkouts/events.py
@@ -0,0 +1,15 @@
+from django.utils.translation import ugettext_lazy as _
+
+HISTORY_DOCUMENT_CHECKED_OUT = {
+    'namespace': 'checkouts', 'name': 'document_checked_out',
+    'label': _(u'Document checked out'),
+    'summary': _(u'Document "%(document)s" checked out by %(fullname)s.'),
+    'expressions': {'fullname': 'user.get_full_name() if user.get_full_name() else user'}
+}
+
+HISTORY_DOCUMENT_CHECKED_IN = {
+    'namespace': 'checkouts', 'name': 'document_checked_in',
+    'label': _(u'Document checked in'),
+    'summary': _(u'Document "%(document)s" checked in by %(fullname)s.'),
+    'expressions': {'fullname': 'user.get_full_name() if user.get_full_name() else user'}
+}
diff --git a/apps/checkouts/exceptions.py b/apps/checkouts/exceptions.py
new file mode 100644
index 0000000000..e27b9645de
--- /dev/null
+++ b/apps/checkouts/exceptions.py
@@ -0,0 +1,11 @@
+class DocumentNotCheckedOut(Exception):
+    """
+    Raised when trying to checkin a document that is not checkedout
+    """
+    pass
+    
+class DocumentAlreadyCheckedOut(Exception):
+    """
+    Raised when trying to checkout an already checkedout document
+    """
+    pass
diff --git a/apps/checkouts/forms.py b/apps/checkouts/forms.py
new file mode 100644
index 0000000000..80fb3091f9
--- /dev/null
+++ b/apps/checkouts/forms.py
@@ -0,0 +1,26 @@
+from __future__ import absolute_import
+
+from django import forms
+from django.utils.translation import ugettext_lazy as _
+
+from .models import DocumentCheckout
+from .exceptions import DocumentAlreadyCheckedOut
+from .widgets import SplitTimeDeltaField
+
+
+class DocumentCheckoutForm(forms.ModelForm):
+    expiration_datetime = SplitTimeDeltaField()
+
+    class Meta:
+        model = DocumentCheckout
+        exclude = ('checkout_datetime', 'user_content_type', 'user_object_id')
+
+        widgets = {
+            'document': forms.widgets.HiddenInput(),
+        }     
+
+    def clean_document(self):
+        document = self.cleaned_data['document']
+        if document.is_checked_out():
+            raise DocumentAlreadyCheckedOut
+        return document
diff --git a/apps/checkouts/links.py b/apps/checkouts/links.py
new file mode 100644
index 0000000000..5583dfe5b3
--- /dev/null
+++ b/apps/checkouts/links.py
@@ -0,0 +1,21 @@
+from __future__ import absolute_import
+
+from django.utils.translation import ugettext_lazy as _
+
+from documents.permissions import PERMISSION_DOCUMENT_VIEW
+
+from .permissions import (PERMISSION_DOCUMENT_CHECKOUT, PERMISSION_DOCUMENT_CHECKIN, PERMISSION_DOCUMENT_CHECKIN_OVERRIDE)
+
+
+def is_checked_out(context):
+    return context['object'].is_checked_out()
+
+
+def is_not_checked_out(context):
+    return not context['object'].is_checked_out()
+
+
+checkout_list = {'text': _(u'checkouts'), 'view': 'checkout_list', 'famfam': 'basket'}
+checkout_document = {'text': _('check out document'), 'view': 'checkout_document', 'args': 'object.pk', 'famfam': 'basket_put', 'condition': is_not_checked_out, 'permissions': [PERMISSION_DOCUMENT_CHECKOUT]}
+checkin_document = {'text': _('check in document'), 'view': 'checkin_document', 'args': 'object.pk', 'famfam': 'basket_remove', 'condition': is_checked_out, 'permissions': [PERMISSION_DOCUMENT_CHECKIN, PERMISSION_DOCUMENT_CHECKIN_OVERRIDE]}
+checkout_info = {'text': _('check in/out'), 'view': 'checkout_info', 'args': 'object.pk', 'famfam': 'basket', 'children_views': ['checkout_document', 'checkin_document'], 'permissions': [PERMISSION_DOCUMENT_CHECKIN, PERMISSION_DOCUMENT_CHECKIN_OVERRIDE, PERMISSION_DOCUMENT_CHECKOUT]}
diff --git a/apps/checkouts/literals.py b/apps/checkouts/literals.py
new file mode 100644
index 0000000000..23e9920984
--- /dev/null
+++ b/apps/checkouts/literals.py
@@ -0,0 +1,16 @@
+from __future__ import absolute_import
+
+from django.utils.translation import ugettext_lazy as _
+
+STATE_CHECKED_OUT = 'checkedout'
+STATE_CHECKED_IN = 'checkedin'
+
+STATE_ICONS = {
+    STATE_CHECKED_OUT: 'basket_put.png',
+    STATE_CHECKED_IN: 'traffic_lights_green.png',
+}
+
+STATE_LABELS = {
+    STATE_CHECKED_OUT: _(u'checked out'),
+    STATE_CHECKED_IN: _(u'checked in/available'),
+}
diff --git a/apps/checkouts/managers.py b/apps/checkouts/managers.py
new file mode 100644
index 0000000000..c1185651ef
--- /dev/null
+++ b/apps/checkouts/managers.py
@@ -0,0 +1,93 @@
+from __future__ import absolute_import
+
+import datetime
+import logging
+
+from django.db import models
+from django.core.exceptions import PermissionDenied
+
+from documents.models import Document
+from history.api import create_history
+from permissions.models import Permission
+from acls.models import AccessEntry
+
+from .exceptions import DocumentNotCheckedOut
+from .literals import STATE_CHECKED_OUT, STATE_CHECKED_IN
+from .events import HISTORY_DOCUMENT_CHECKED_IN
+from .permissions import PERMISSION_DOCUMENT_RESTRICTIONS_OVERRIDE
+
+logger = logging.getLogger(__name__)
+
+
+class DocumentCheckoutManager(models.Manager):
+    def checked_out_documents(self):
+        return Document.objects.filter(pk__in=self.model.objects.all().values_list('document__pk', flat=True))
+        
+    def expired_check_outs(self):
+        expired_list = Document.objects.filter(pk__in=self.model.objects.filter(expiration_datetime__lte=datetime.datetime.now()).values_list('document__pk', flat=True))
+        logger.debug('expired_list: %s' % expired_list)
+        return expired_list
+
+    def check_in_expired_check_outs(self):
+        for document in self.expired_check_outs():
+            document.check_in()
+
+    def is_document_checked_out(self, document):
+        if self.model.objects.filter(document=document):
+            return True
+        else:
+            return False
+            
+    def check_in_document(self, document, user=None):
+        try:
+            document_checkout = self.model.objects.get(document=document)
+        except self.model.DoesNotExist:
+            raise DocumentNotCheckedOut
+        else:
+            if user:
+                create_history(HISTORY_DOCUMENT_CHECKED_IN, source_object=document, data={'user': user, 'document': document})
+            document_checkout.delete()
+            
+    def document_checkout_info(self, document):
+        try:
+            return self.model.objects.get(document=document)
+        except self.model.DoesNotExist:
+            raise DocumentNotCheckedOut
+
+    def document_checkout_state(self, document):
+        if self.is_document_checked_out(document):
+            return STATE_CHECKED_OUT
+        else:
+            return STATE_CHECKED_IN
+
+    def is_document_new_versions_allowed(self, document, user=None):
+        try:
+            checkout_info = self.document_checkout_info(document)
+        except DocumentNotCheckedOut:
+            return True
+        else:
+            if not user:
+                return not checkout_info.block_new_version
+            else:
+                if user.is_staff or user.is_superuser:
+                    # Allow anything to superusers and staff
+                    return True
+
+                if user == checkout_info.user_object:
+                    # Allow anything to the user who checked out this document
+                    True
+                else:
+                    # If not original user check to see if user has global or this document's PERMISSION_DOCUMENT_RESTRICTIONS_OVERRIDE permission
+                    try:
+                        Permission.objects.check_permissions(user, [PERMISSION_DOCUMENT_RESTRICTIONS_OVERRIDE])
+                    except PermissionDenied:
+                        try:
+                            AccessEntry.objects.check_accesses([PERMISSION_DOCUMENT_RESTRICTIONS_OVERRIDE], user, document)
+                        except PermissionDenied:
+                            # Last resort check if original user enabled restriction
+                            return not checkout_info.block_new_version
+                        else:
+                            return True                        
+                    else:
+                        return True                    
+            
diff --git a/apps/checkouts/migrations/0001_initial.py b/apps/checkouts/migrations/0001_initial.py
new file mode 100644
index 0000000000..85ee9306e2
--- /dev/null
+++ b/apps/checkouts/migrations/0001_initial.py
@@ -0,0 +1,122 @@
+# -*- coding: utf-8 -*-
+import datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Adding model 'DocumentCheckout'
+        db.create_table('checkouts_documentcheckout', (
+            ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('document', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['documents.Document'], unique=True)),
+            ('checkout_datetime', self.gf('django.db.models.fields.DateTimeField')(default=datetime.datetime(2012, 6, 13, 0, 0))),
+            ('expiration_datetime', self.gf('django.db.models.fields.DateTimeField')()),
+            ('block_new_version', self.gf('django.db.models.fields.BooleanField')(default=False)),
+        ))
+        db.send_create_signal('checkouts', ['DocumentCheckout'])
+
+
+    def backwards(self, orm):
+        # Deleting model 'DocumentCheckout'
+        db.delete_table('checkouts_documentcheckout')
+
+
+    models = {
+        'auth.group': {
+            'Meta': {'object_name': 'Group'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '80'}),
+            'permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'})
+        },
+        'auth.permission': {
+            'Meta': {'ordering': "('content_type__app_label', 'content_type__model', 'codename')", 'unique_together': "(('content_type', 'codename'),)", 'object_name': 'Permission'},
+            'codename': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'auth.user': {
+            'Meta': {'object_name': 'User'},
+            'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
+            'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'groups': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Group']", 'symmetrical': 'False', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'is_staff': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'is_superuser': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'last_login': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'password': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
+            'user_permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'}),
+            'username': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'})
+        },
+        'checkouts.documentcheckout': {
+            'Meta': {'object_name': 'DocumentCheckout'},
+            'block_new_version': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'checkout_datetime': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime(2012, 6, 13, 0, 0)'}),
+            'document': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['documents.Document']", 'unique': 'True'}),
+            'expiration_datetime': ('django.db.models.fields.DateTimeField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'})
+        },
+        'comments.comment': {
+            'Meta': {'ordering': "('submit_date',)", 'object_name': 'Comment', 'db_table': "'django_comments'"},
+            'comment': ('django.db.models.fields.TextField', [], {'max_length': '3000'}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'content_type_set_for_comment'", 'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'ip_address': ('django.db.models.fields.IPAddressField', [], {'max_length': '15', 'null': 'True', 'blank': 'True'}),
+            'is_public': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'is_removed': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'object_pk': ('django.db.models.fields.TextField', [], {}),
+            'site': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['sites.Site']"}),
+            'submit_date': ('django.db.models.fields.DateTimeField', [], {'default': 'None'}),
+            'user': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'comment_comments'", 'null': 'True', 'to': "orm['auth.User']"}),
+            'user_email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
+            'user_name': ('django.db.models.fields.CharField', [], {'max_length': '50', 'blank': 'True'}),
+            'user_url': ('django.db.models.fields.URLField', [], {'max_length': '200', 'blank': 'True'})
+        },
+        'contenttypes.contenttype': {
+            'Meta': {'ordering': "('name',)", 'unique_together': "(('app_label', 'model'),)", 'object_name': 'ContentType', 'db_table': "'django_content_type'"},
+            'app_label': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'model': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        'documents.document': {
+            'Meta': {'ordering': "['-date_added']", 'object_name': 'Document'},
+            'date_added': ('django.db.models.fields.DateTimeField', [], {'db_index': 'True'}),
+            'description': ('django.db.models.fields.TextField', [], {'null': 'True', 'blank': 'True'}),
+            'document_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['documents.DocumentType']", 'null': 'True', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'uuid': ('django.db.models.fields.CharField', [], {'max_length': '48', 'blank': 'True'})
+        },
+        'documents.documenttype': {
+            'Meta': {'ordering': "['name']", 'object_name': 'DocumentType'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '32'})
+        },
+        'sites.site': {
+            'Meta': {'ordering': "('domain',)", 'object_name': 'Site', 'db_table': "'django_site'"},
+            'domain': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'taggit.tag': {
+            'Meta': {'object_name': 'Tag'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'slug': ('django.db.models.fields.SlugField', [], {'unique': 'True', 'max_length': '100'})
+        },
+        'taggit.taggeditem': {
+            'Meta': {'object_name': 'TaggedItem'},
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'taggit_taggeditem_tagged_items'", 'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'object_id': ('django.db.models.fields.IntegerField', [], {'db_index': 'True'}),
+            'tag': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'taggit_taggeditem_items'", 'to': "orm['taggit.Tag']"})
+        }
+    }
+
+    complete_apps = ['checkouts']
\ No newline at end of file
diff --git a/apps/checkouts/migrations/0002_auto__add_field_documentcheckout_user_content_type__add_field_document.py b/apps/checkouts/migrations/0002_auto__add_field_documentcheckout_user_content_type__add_field_document.py
new file mode 100644
index 0000000000..be5474450e
--- /dev/null
+++ b/apps/checkouts/migrations/0002_auto__add_field_documentcheckout_user_content_type__add_field_document.py
@@ -0,0 +1,133 @@
+# -*- coding: utf-8 -*-
+import datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Adding field 'DocumentCheckout.user_content_type'
+        db.add_column('checkouts_documentcheckout', 'user_content_type',
+                      self.gf('django.db.models.fields.related.ForeignKey')(to=orm['contenttypes.ContentType'], null=True, blank=True),
+                      keep_default=False)
+
+        # Adding field 'DocumentCheckout.user_object_id'
+        db.add_column('checkouts_documentcheckout', 'user_object_id',
+                      self.gf('django.db.models.fields.PositiveIntegerField')(null=True, blank=True),
+                      keep_default=False)
+
+
+        # Changing field 'DocumentCheckout.checkout_datetime'
+        db.alter_column('checkouts_documentcheckout', 'checkout_datetime', self.gf('django.db.models.fields.DateTimeField')(null=True))
+
+    def backwards(self, orm):
+        # Deleting field 'DocumentCheckout.user_content_type'
+        db.delete_column('checkouts_documentcheckout', 'user_content_type_id')
+
+        # Deleting field 'DocumentCheckout.user_object_id'
+        db.delete_column('checkouts_documentcheckout', 'user_object_id')
+
+
+        # Changing field 'DocumentCheckout.checkout_datetime'
+        db.alter_column('checkouts_documentcheckout', 'checkout_datetime', self.gf('django.db.models.fields.DateTimeField')())
+
+    models = {
+        'auth.group': {
+            'Meta': {'object_name': 'Group'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '80'}),
+            'permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'})
+        },
+        'auth.permission': {
+            'Meta': {'ordering': "('content_type__app_label', 'content_type__model', 'codename')", 'unique_together': "(('content_type', 'codename'),)", 'object_name': 'Permission'},
+            'codename': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'auth.user': {
+            'Meta': {'object_name': 'User'},
+            'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
+            'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'groups': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Group']", 'symmetrical': 'False', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'is_staff': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'is_superuser': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'last_login': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'password': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
+            'user_permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'}),
+            'username': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'})
+        },
+        'checkouts.documentcheckout': {
+            'Meta': {'object_name': 'DocumentCheckout'},
+            'block_new_version': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'checkout_datetime': ('django.db.models.fields.DateTimeField', [], {'null': 'True', 'blank': 'True'}),
+            'document': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['documents.Document']", 'unique': 'True'}),
+            'expiration_datetime': ('django.db.models.fields.DateTimeField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'user_content_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['contenttypes.ContentType']", 'null': 'True', 'blank': 'True'}),
+            'user_object_id': ('django.db.models.fields.PositiveIntegerField', [], {'null': 'True', 'blank': 'True'})
+        },
+        'comments.comment': {
+            'Meta': {'ordering': "('submit_date',)", 'object_name': 'Comment', 'db_table': "'django_comments'"},
+            'comment': ('django.db.models.fields.TextField', [], {'max_length': '3000'}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'content_type_set_for_comment'", 'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'ip_address': ('django.db.models.fields.IPAddressField', [], {'max_length': '15', 'null': 'True', 'blank': 'True'}),
+            'is_public': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'is_removed': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'object_pk': ('django.db.models.fields.TextField', [], {}),
+            'site': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['sites.Site']"}),
+            'submit_date': ('django.db.models.fields.DateTimeField', [], {'default': 'None'}),
+            'user': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'comment_comments'", 'null': 'True', 'to': "orm['auth.User']"}),
+            'user_email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
+            'user_name': ('django.db.models.fields.CharField', [], {'max_length': '50', 'blank': 'True'}),
+            'user_url': ('django.db.models.fields.URLField', [], {'max_length': '200', 'blank': 'True'})
+        },
+        'contenttypes.contenttype': {
+            'Meta': {'ordering': "('name',)", 'unique_together': "(('app_label', 'model'),)", 'object_name': 'ContentType', 'db_table': "'django_content_type'"},
+            'app_label': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'model': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        'documents.document': {
+            'Meta': {'ordering': "['-date_added']", 'object_name': 'Document'},
+            'date_added': ('django.db.models.fields.DateTimeField', [], {'db_index': 'True'}),
+            'description': ('django.db.models.fields.TextField', [], {'null': 'True', 'blank': 'True'}),
+            'document_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['documents.DocumentType']", 'null': 'True', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'uuid': ('django.db.models.fields.CharField', [], {'max_length': '48', 'blank': 'True'})
+        },
+        'documents.documenttype': {
+            'Meta': {'ordering': "['name']", 'object_name': 'DocumentType'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '32'})
+        },
+        'sites.site': {
+            'Meta': {'ordering': "('domain',)", 'object_name': 'Site', 'db_table': "'django_site'"},
+            'domain': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'taggit.tag': {
+            'Meta': {'object_name': 'Tag'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'slug': ('django.db.models.fields.SlugField', [], {'unique': 'True', 'max_length': '100'})
+        },
+        'taggit.taggeditem': {
+            'Meta': {'object_name': 'TaggedItem'},
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'taggit_taggeditem_tagged_items'", 'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'object_id': ('django.db.models.fields.IntegerField', [], {'db_index': 'True'}),
+            'tag': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'taggit_taggeditem_items'", 'to': "orm['taggit.Tag']"})
+        }
+    }
+
+    complete_apps = ['checkouts']
\ No newline at end of file
diff --git a/apps/checkouts/migrations/__init__.py b/apps/checkouts/migrations/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/apps/checkouts/models.py b/apps/checkouts/models.py
new file mode 100644
index 0000000000..819b8856c3
--- /dev/null
+++ b/apps/checkouts/models.py
@@ -0,0 +1,56 @@
+from __future__ import absolute_import
+
+import logging
+import datetime
+
+from django.db import models, IntegrityError
+from django.utils.translation import ugettext_lazy as _
+from django.contrib.contenttypes.models import ContentType
+from django.contrib.contenttypes import generic
+
+from documents.models import Document
+from history.api import create_history
+
+from .managers import DocumentCheckoutManager
+from .exceptions import DocumentAlreadyCheckedOut
+from .events import HISTORY_DOCUMENT_CHECKED_OUT
+
+logger = logging.getLogger(__name__)
+
+
+class DocumentCheckout(models.Model):
+    """
+    Model to store the state and information of a document checkout
+    """
+    document = models.ForeignKey(Document, verbose_name=_(u'document'), unique=True)
+    checkout_datetime = models.DateTimeField(verbose_name=_(u'check out date and time'), blank=True, null=True)
+    expiration_datetime = models.DateTimeField(verbose_name=_(u'check out expiration date and time'), help_text=_(u'Amount of time to hold the document checked out in minutes.'))
+    user_content_type = models.ForeignKey(ContentType, null=True, blank=True)  # blank and null added for ease of db migration
+    user_object_id = models.PositiveIntegerField(null=True, blank=True)
+    user_object = generic.GenericForeignKey(ct_field='user_content_type', fk_field='user_object_id')
+
+    block_new_version = models.BooleanField(default=True, verbose_name=_(u'block new version upload'), help_text=_(u'Do not allow new version of this document to be uploaded.'))
+
+    #block_metadata
+    #block_editing
+    #block tag add/remove
+    
+    objects = DocumentCheckoutManager()
+    
+    def __unicode__(self):
+        return unicode(self.document)
+
+    def save(self, *args, **kwargs):
+        if not self.pk:
+            self.checkout_datetime = datetime.datetime.now()
+        result = super(DocumentCheckout, self).save(*args, **kwargs)
+        create_history(HISTORY_DOCUMENT_CHECKED_OUT, source_object=self.document, data={'user': self.user_object, 'document': self.document})
+        return result
+    
+    @models.permalink
+    def get_absolute_url(self):
+        return ('checkout_info', [self.document.pk])        
+        
+    class Meta:
+        verbose_name = _(u'document checkout')
+        verbose_name_plural = _(u'document checkouts')
diff --git a/apps/checkouts/permissions.py b/apps/checkouts/permissions.py
new file mode 100644
index 0000000000..19430381b8
--- /dev/null
+++ b/apps/checkouts/permissions.py
@@ -0,0 +1,13 @@
+from __future__ import absolute_import
+
+from django.utils.translation import ugettext_lazy as _
+
+from permissions.models import PermissionNamespace, Permission
+
+namespace = PermissionNamespace('checkouts', _(u'Document checkout'))
+
+PERMISSION_DOCUMENT_CHECKOUT = Permission.objects.register(namespace, 'checkout_document', _(u'Check out documents'))
+PERMISSION_DOCUMENT_CHECKIN = Permission.objects.register(namespace, 'checkin_document', _(u'Check in documents'))
+PERMISSION_DOCUMENT_CHECKIN_OVERRIDE = Permission.objects.register(namespace, 'checkin_document_override', _(u'Forcefully check in documents'))
+PERMISSION_DOCUMENT_RESTRICTIONS_OVERRIDE = Permission.objects.register(namespace, 'checkout_restrictions_override', _(u'Allow overriding check out restrictions'))
+
diff --git a/apps/checkouts/static/images/icons/basket_put.png b/apps/checkouts/static/images/icons/basket_put.png
new file mode 100644
index 0000000000..66e7fcec1a
Binary files /dev/null and b/apps/checkouts/static/images/icons/basket_put.png differ
diff --git a/apps/checkouts/static/images/icons/basket_remove.png b/apps/checkouts/static/images/icons/basket_remove.png
new file mode 100644
index 0000000000..0d8c5a36a3
Binary files /dev/null and b/apps/checkouts/static/images/icons/basket_remove.png differ
diff --git a/apps/checkouts/static/images/icons/traffic_lights_green.png b/apps/checkouts/static/images/icons/traffic_lights_green.png
new file mode 100644
index 0000000000..bd53d89990
Binary files /dev/null and b/apps/checkouts/static/images/icons/traffic_lights_green.png differ
diff --git a/apps/checkouts/tasks.py b/apps/checkouts/tasks.py
new file mode 100644
index 0000000000..d97f08f54b
--- /dev/null
+++ b/apps/checkouts/tasks.py
@@ -0,0 +1,24 @@
+from __future__ import absolute_import
+
+import logging
+
+from lock_manager import Lock, LockError
+
+from .models import DocumentCheckout
+
+LOCK_EXPIRE = 50
+logger = logging.getLogger(__name__)
+
+
+def task_check_expired_check_outs():
+    logger.debug('executing...')
+    lock_id = u'task_expired_check_outs'
+    try:
+        logger.debug('trying to acquire lock: %s' % lock_id)
+        lock = Lock.acquire_lock(lock_id, LOCK_EXPIRE)
+        logger.debug('acquired lock: %s' % lock_id)
+        DocumentCheckout.objects.check_in_expired_check_outs()
+        lock.release()
+    except LockError:
+        logger.debug('unable to obtain lock')
+        pass
diff --git a/apps/checkouts/urls.py b/apps/checkouts/urls.py
new file mode 100644
index 0000000000..6dd1d8fdd8
--- /dev/null
+++ b/apps/checkouts/urls.py
@@ -0,0 +1,8 @@
+from django.conf.urls.defaults import patterns, url
+
+urlpatterns = patterns('checkouts.views',
+    url(r'^list/$', 'checkout_list', (), 'checkout_list'),
+    url(r'^(?P<document_pk>\d+)/check/out/$', 'checkout_document', (), 'checkout_document'),
+    url(r'^(?P<document_pk>\d+)/check/in/$', 'checkin_document', (), 'checkin_document'),
+    url(r'^(?P<document_pk>\d+)/check/info/$', 'checkout_info', (), 'checkout_info'),
+)
diff --git a/apps/checkouts/views.py b/apps/checkouts/views.py
new file mode 100644
index 0000000000..ff52336f38
--- /dev/null
+++ b/apps/checkouts/views.py
@@ -0,0 +1,134 @@
+from __future__ import absolute_import
+
+from django.utils.translation import ugettext_lazy as _
+from django.http import HttpResponseRedirect
+from django.shortcuts import render_to_response, get_object_or_404
+from django.template import RequestContext
+from django.contrib import messages
+from django.core.urlresolvers import reverse
+from django.core.exceptions import PermissionDenied
+
+from documents.views import document_list
+from documents.models import Document
+
+from permissions.models import Permission
+from acls.models import AccessEntry
+from common.utils import get_object_name
+from common.utils import encapsulate
+
+from .models import DocumentCheckout
+from .permissions import PERMISSION_DOCUMENT_CHECKOUT, PERMISSION_DOCUMENT_CHECKIN
+from .forms import DocumentCheckoutForm
+from .exceptions import DocumentAlreadyCheckedOut, DocumentNotCheckedOut
+from .literals import STATE_CHECKED_OUT, STATE_CHECKED_IN, STATE_ICONS, STATE_LABELS
+from .widgets import checkout_widget
+
+
+def checkout_list(request):
+
+    return document_list(
+        request,
+        object_list=DocumentCheckout.objects.checked_out_documents(),
+        title=_(u'checked out documents'),
+        extra_context={
+                'extra_columns': [
+                    {'name': _(u'checkout user'), 'attribute': encapsulate(lambda document: get_object_name(document.checkout_info().user_object, display_object_type=False))},
+                    {'name': _(u'checkout time and date'), 'attribute': encapsulate(lambda document: document.checkout_info().checkout_datetime)},
+                    {'name': _(u'checkout expiration'), 'attribute': encapsulate(lambda document: document.checkout_info().expiration_datetime)},
+                ],
+        }
+    )
+
+
+def checkout_info(request, document_pk):
+    document = get_object_or_404(Document, pk=document_pk)
+    try:
+        Permission.objects.check_permissions(request.user, [PERMISSION_DOCUMENT_CHECKOUT, PERMISSION_DOCUMENT_CHECKIN])
+    except PermissionDenied:
+        AccessEntry.objects.check_accesses([PERMISSION_DOCUMENT_CHECKOUT, PERMISSION_DOCUMENT_CHECKIN], request.user, document)
+
+    paragraphs = [checkout_widget(document)]
+
+    if document.is_checked_out():
+        checkout_info = document.checkout_info()
+        paragraphs.append(_(u'User: %s') % get_object_name(checkout_info.user_object, display_object_type=False))
+        paragraphs.append(_(u'Check out time: %s') % checkout_info.checkout_datetime)
+        paragraphs.append(_(u'Check out expiration: %s') % checkout_info.expiration_datetime)
+        paragraphs.append(_(u'New versions allowed: %s') % (_(u'yes') if not checkout_info.block_new_version else _(u'no')))
+        
+    return render_to_response('generic_template.html', {
+        'paragraphs': paragraphs,
+        'object': document,
+        'title': _(u'Check out details for document: %s') % document
+    }, context_instance=RequestContext(request))    
+
+
+def checkout_document(request, document_pk):
+    document = get_object_or_404(Document, pk=document_pk)
+    try:
+        Permission.objects.check_permissions(request.user, [PERMISSION_DOCUMENT_CHECKOUT])
+    except PermissionDenied:
+        AccessEntry.objects.check_access(PERMISSION_DOCUMENT_CHECKOUT, request.user, document)
+        
+    if request.method == 'POST':
+        form = DocumentCheckoutForm(data=request.POST, initial={'document': document})
+        try:
+            if form.is_valid():
+                try:
+                    document_checkout = form.save(commit=False)
+                    document_checkout.user_object = request.user
+                    document_checkout.save()
+                except Exception, exc:
+                    messages.error(request, _(u'Error trying to check out document; %s') % exc)
+                else:
+                    messages.success(request, _(u'Document "%s" checked out successfully.') % document)
+                    return HttpResponseRedirect(reverse('checkout_info', args=[document.pk]))
+        except DocumentAlreadyCheckedOut:
+            messages.error(request, _(u'Document already checked out.'))
+            return HttpResponseRedirect(reverse('checkout_info', args=[document.pk]))
+    else:
+        form = DocumentCheckoutForm(initial={'document': document})
+
+    return render_to_response('generic_form.html', {
+        'form': form,
+        'object': document,
+        'title': _(u'Check out document: %s') % document
+    }, context_instance=RequestContext(request))    
+
+
+def checkin_document(request, document_pk):
+    document = get_object_or_404(Document, pk=document_pk)
+    post_action_redirect = reverse('checkout_info', args=[document.pk])
+    # TODO: add forcefull checkin
+    # TODO: check user
+    try:
+        Permission.objects.check_permissions(request.user, [PERMISSION_DOCUMENT_CHECKIN])
+    except PermissionDenied:
+        AccessEntry.objects.check_access(PERMISSION_DOCUMENT_CHECKIN, request.user, document)
+
+    previous = request.POST.get('previous', request.GET.get('previous', request.META.get('HTTP_REFERER', '/')))
+    next = request.POST.get('next', request.GET.get('next', post_action_redirect if post_action_redirect else request.META.get('HTTP_REFERER', '/')))
+
+    if request.method == 'POST':
+        try:
+            document.check_in(user=request.user)
+        except DocumentNotCheckedOut:
+            messages.error(request, _(u'Document has not been checked out.'))
+        except Exception, exc:
+            messages.error(request, _(u'Error trying to check in document; %s') % exc)
+        else:
+            messages.success(request, _(u'Document "%s" checked in successfully.') % document)
+            return HttpResponseRedirect(next)
+
+    context = {
+        'object_name': _(u'document'),
+        'delete_view': False,
+        'previous': previous,
+        'next': next,
+        'form_icon': u'basket_remove.png',
+        'object': document,
+        'title': _(u'Are you sure you wish to check in document: %s') % document
+    }
+
+    return render_to_response('generic_confirm.html', context,
+        context_instance=RequestContext(request))
diff --git a/apps/checkouts/widgets.py b/apps/checkouts/widgets.py
new file mode 100644
index 0000000000..cd5f3d8f70
--- /dev/null
+++ b/apps/checkouts/widgets.py
@@ -0,0 +1,107 @@
+from __future__ import absolute_import
+
+import datetime
+
+from django import forms
+from django.utils.translation import ugettext_lazy as _
+from django.utils.safestring import mark_safe
+from django.conf import settings
+from django.core import validators
+
+from .literals import STATE_CHECKED_OUT, STATE_CHECKED_IN, STATE_ICONS, STATE_LABELS
+
+
+def checkout_widget(document):
+    checkout_state = document.checkout_state()
+
+    widget = (u'<img style="vertical-align: middle;" src="%simages/icons/%s" />' % (settings.STATIC_URL, STATE_ICONS[checkout_state]))
+    return _(u'Document status: %(widget)s %(text)s') % {
+        'widget': mark_safe(widget),
+        'text': STATE_LABELS[checkout_state]
+    }
+
+
+class SplitDeltaWidget(forms.widgets.MultiWidget):
+    """
+    A Widget that splits a timedelta input into three <input type="text"> boxes.
+    """
+    def __init__(self, attrs=None):
+        widgets = (
+            forms.widgets.TextInput(attrs={'maxlength': 3, 'style':'width: 5em;', 'placeholder': _(u'Days')}),
+            forms.widgets.TextInput(attrs={'maxlength': 4, 'style':'width: 5em;', 'placeholder': _(u'Hours')}),
+            forms.widgets.TextInput(attrs={'maxlength': 5, 'style':'width: 5em;', 'placeholder': _(u'Minutes')}),
+        )
+        super(SplitDeltaWidget, self).__init__(widgets, attrs)
+
+    def decompress(self, value):
+        if value:
+            return [value.days, value.seconds / 3600, (value.seconds / 60) % 60]
+        return [None, None, None]
+
+    def value_from_datadict(self, data, files, name):
+        return [data.get('expiration_datetime_0', 0) or 0, data.get('expiration_datetime_1', 0) or 0, data.get('expiration_datetime_2', 0) or 0]
+
+
+class SplitHiddenDeltaWidget(forms.widgets.SplitDateTimeWidget):
+    """
+    A Widget that splits a timedelta input into three <input type="hidden"> inputs.
+    """
+    is_hidden = True
+
+    def __init__(self, attrs=None):
+        super(SplitHiddenDeltaWidget, self).__init__(attrs, date_format, time_format)
+        for widget in self.widgets:
+            widget.input_type = 'hidden'
+            widget.is_hidden = True
+
+
+class SplitTimeDeltaField(forms.MultiValueField):
+    widget = SplitDeltaWidget
+    hidden_widget = SplitHiddenDeltaWidget
+    default_error_messages = {
+        'invalid_days': _(u'Enter a valid number of days.'),
+        'invalid_hours': _(u'Enter a valid number of hours.'),
+        'invalid_minutes': _(u'Enter a valid number of minutes.'),
+        'invalid_timedelta': _(u'Enter a valid time difference.'),
+    }
+
+    def __init__(self, *args, **kwargs):
+        errors = self.default_error_messages.copy()
+        if 'error_messages' in kwargs:
+            errors.update(kwargs['error_messages'])
+        localize = kwargs.get('localize', False)
+        fields = (
+            forms.IntegerField(min_value=0,
+                error_messages={'invalid': errors['invalid_days']},
+                localize=localize                
+            ),
+            forms.IntegerField(min_value=0,
+                error_messages={'invalid': errors['invalid_hours']},
+                localize=localize                
+            ),
+            forms.IntegerField(min_value=0,
+                error_messages={'invalid': errors['invalid_minutes']},
+                localize=localize                
+            ),
+        )
+        super(SplitTimeDeltaField, self).__init__(fields, *args, **kwargs)
+        self.help_text = _(u'Amount of time to hold the document in the checked out state in days, hours and/or minutes.')
+        self.label = _('Check out expiration date and time')
+
+    def compress(self, data_list):
+        if data_list == [0, 0, 0]:
+            raise forms.ValidationError(self.error_messages['invalid_timedelta'])
+            
+        if data_list:
+            # Raise a validation error if time or date is empty
+            # (possible if SplitDateTimeField has required=False).
+            if data_list[0] in validators.EMPTY_VALUES:
+                raise forms.ValidationError(self.error_messages['invalid_days'])
+            if data_list[1] in validators.EMPTY_VALUES:
+                raise forms.ValidationError(self.error_messages['invalid_hours'])
+            if data_list[2] in validators.EMPTY_VALUES:
+                raise forms.ValidationError(self.error_messages['invalid_minutes'])       
+                
+            timedelta = datetime.timedelta(days=data_list[0], hours=data_list[1], minutes=data_list[2])
+            return datetime.datetime.now() + timedelta
+        return None
diff --git a/apps/documents/exceptions.py b/apps/documents/exceptions.py
new file mode 100644
index 0000000000..e3ab3eec34
--- /dev/null
+++ b/apps/documents/exceptions.py
@@ -0,0 +1,6 @@
+class NewDocumentVersionNotAllowed(Exception):
+    """
+    Uploading new versions for this document is not allowed
+    Current reasons:  Document is in checked out state
+    """
+    pass
diff --git a/apps/documents/models.py b/apps/documents/models.py
index c820780c3b..eb94051902 100644
--- a/apps/documents/models.py
+++ b/apps/documents/models.py
@@ -37,6 +37,7 @@ from .managers import DocumentPageTransformationManager
 from .utils import document_save_to_temp_dir
 from .literals import (RELEASE_LEVEL_FINAL, RELEASE_LEVEL_CHOICES,
     VERSION_UPDATE_MAJOR, VERSION_UPDATE_MINOR, VERSION_UPDATE_MICRO)
+from .exceptions import NewDocumentVersionNotAllowed
 
 # document image cache name hash function
 HASH_FUNCTION = lambda x: hashlib.sha256(x).hexdigest()
@@ -169,8 +170,11 @@ class Document(models.Model):
     def size(self):
         return self.latest_version.size
 
-    def new_version(self, file, comment=None, version_update=None, release_level=None, serial=None):
+    def new_version(self, file, user=None, comment=None, version_update=None, release_level=None, serial=None):
         logger.debug('creating new document version')
+        if not self.is_new_versions_allowed(user=user):
+            raise NewDocumentVersionNotAllowed
+
         if version_update:
             new_version_dict = self.latest_version.get_new_version_dict(version_update)
             logger.debug('new_version_dict: %s' % new_version_dict)
@@ -520,8 +524,14 @@ class DocumentVersion(models.Model):
             return None
             
     def rename(self, new_name):
+        new_filename, new_extension = os.path.splitext(new_name)
         name, extension = os.path.splitext(self.filename)
-        self.filename = u''.join([new_name, extension])
+        
+        # Preserve existing extension if new name doesn't has one
+        if new_extension:
+            extension = new_extension
+
+        self.filename = u''.join([new_filename, extension])
         self.save()
 
 
diff --git a/apps/history/__init__.py b/apps/history/__init__.py
index b0b4025a3e..24469fbd2c 100644
--- a/apps/history/__init__.py
+++ b/apps/history/__init__.py
@@ -6,7 +6,6 @@ from project_tools.api import register_tool
 
 from .permissions import PERMISSION_HISTORY_VIEW
 
-
-history_list = {'text': _(u'history'), 'view': 'history_list', 'famfam': 'book', 'icon': 'book.png', 'permissions': [PERMISSION_HISTORY_VIEW], 'children_view_regex': [r'history_[l,v]']}
+history_list = {'text': _(u'history'), 'view': 'history_list', 'famfam': 'book', 'icon': 'book.png', 'children_view_regex': [r'history_[l,v]']}
 
 register_tool(history_list)
diff --git a/apps/history/views.py b/apps/history/views.py
index 2212c7e5ef..8b29a5d1ca 100644
--- a/apps/history/views.py
+++ b/apps/history/views.py
@@ -19,12 +19,22 @@ from .permissions import PERMISSION_HISTORY_VIEW
 from .widgets import history_entry_object_link, history_entry_summary
 
 
-def history_list(request):
-    Permission.objects.check_permissions(request.user, [PERMISSION_HISTORY_VIEW])
+def history_list(request, object_list=None, title=None, extra_context=None):
+    pre_object_list = object_list if not (object_list is None) else History.objects.all()
+
+    try:
+        Permission.objects.check_permissions(request.user, [PERMISSION_HISTORY_VIEW])
+    except PermissionDenied:
+        # If user doesn't have global permission, get a list of document
+        # for which he/she does hace access use it to filter the
+        # provided object_list
+        final_object_list = AccessEntry.objects.filter_objects_by_access(PERMISSION_HISTORY_VIEW, request.user, pre_object_list, related='content_object')
+    else:
+        final_object_list = pre_object_list
 
     context = {
-        'object_list': History.objects.all(),
-        'title': _(u'history events'),
+        'object_list': final_object_list,
+        'title': title if title else _(u'history events'),
         'extra_columns': [
             {
                 'name': _(u'date and time'),
@@ -42,6 +52,9 @@ def history_list(request):
         'hide_object': True,
     }
 
+    if extra_context:
+        context.update(extra_context)
+
     return render_to_response('generic_list.html', context,
         context_instance=RequestContext(request))
 
@@ -88,11 +101,11 @@ def history_view(request, object_id):
         AccessEntry.objects.check_access(PERMISSION_HISTORY_VIEW, request.user, history.content_object)    
 
     form = HistoryDetailForm(instance=history, extra_fields=[
-        {'label': _(u'Date'), 'field':lambda x: x.datetime.date()},
-        {'label': _(u'Time'), 'field':lambda x: unicode(x.datetime.time()).split('.')[0]},
+        {'label': _(u'Date'), 'field': lambda x: x.datetime.date()},
+        {'label': _(u'Time'), 'field': lambda x: unicode(x.datetime.time()).split('.')[0]},
         {'label': _(u'Object'), 'field': 'content_object'},
         {'label': _(u'Event type'), 'field': lambda x: x.get_label()},
-        {'label': _(u'Event details'), 'field': lambda x: x.get_processed_details()},
+        {'label': _(u'Additional details'), 'field': lambda x: x.get_processed_details() or _(u'None')},
     ])
 
     return render_to_response('generic_detail.html', {
diff --git a/apps/permissions/exceptions.py b/apps/permissions/exceptions.py
new file mode 100644
index 0000000000..14c1eb54f6
--- /dev/null
+++ b/apps/permissions/exceptions.py
@@ -0,0 +1,5 @@
+from django.core.exceptions import PermissionDenied as DjangoPermissionDenied
+
+
+class PermissionDenied(DjangoPermissionDenied):
+    pass
diff --git a/apps/sources/models.py b/apps/sources/models.py
index 0941abd00d..e659b4e60e 100644
--- a/apps/sources/models.py
+++ b/apps/sources/models.py
@@ -114,7 +114,7 @@ class BaseModel(models.Model):
             new_version_data = {}
 
         try:
-            new_version = document.new_version(file=file_object, **new_version_data)
+            new_version = document.new_version(file=file_object, user=user, **new_version_data)
         except Exception:
             # Don't leave the database in a broken state
             # document.delete()
diff --git a/apps/sources/views.py b/apps/sources/views.py
index adb4df3611..0014d9b4cf 100644
--- a/apps/sources/views.py
+++ b/apps/sources/views.py
@@ -15,6 +15,7 @@ from documents.permissions import (PERMISSION_DOCUMENT_CREATE,
     PERMISSION_DOCUMENT_NEW_VERSION)
 from documents.models import DocumentType, Document
 from documents.conf.settings import THUMBNAIL_SIZE
+from documents.exceptions import NewDocumentVersionNotAllowed
 from metadata.api import decode_metadata_from_url, metadata_repr_as_list
 from permissions.models import Permission
 from common.utils import encapsulate
@@ -174,6 +175,8 @@ def upload_interactive(request, source_type=None, source_id=None, document_pk=No
                                 messages.warning(request, _(u'File was not a compressed file, uploaded as it was.'))
 
                             return HttpResponseRedirect(request.get_full_path())
+                    except NewDocumentVersionNotAllowed:
+                        messages.error(request, _(u'New version uploads are not allowed for this document.'))
                     except Exception, e:
                         if settings.DEBUG:
                             raise
@@ -253,6 +256,8 @@ def upload_interactive(request, source_type=None, source_id=None, document_pk=No
                             return HttpResponseRedirect(reverse('document_view_simple', args=[document.pk]))
                         else:
                             return HttpResponseRedirect(request.get_full_path())
+                    except NewDocumentVersionNotAllowed:
+                        messages.error(request, _(u'New version uploads are not allowed for this document.'))
                     except Exception, e:
                         if settings.DEBUG:
                             raise
diff --git a/docs/index.rst b/docs/index.rst
index fe94d819c9..5bb72eba86 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -6,7 +6,7 @@ Mayan EDMS documentation
 ========================
 
 .. rubric:: `Open source`_, Django_ based document manager with custom
-            metadata_ indexing_, file serving integration, OCR_ capabilities,
+            metadata_ indexing_, file serving integration, `checking out and in`_, OCR_ capabilities,
             document versioning_ and `digital signature verification`_.
 
 .. _Django: http://www.djangoproject.com/
@@ -16,6 +16,7 @@ Mayan EDMS documentation
 .. _metadata: http://en.wikipedia.org/wiki/Metadata
 .. _indexing: http://en.wikipedia.org/wiki/Index_card
 .. _Open source: http://en.wikipedia.org/wiki/Open_source
+.. _checking out and in: http://en.wikipedia.org/wiki/Revision_control
 
 On the Web
 =====================
@@ -54,7 +55,7 @@ Understanding Mayan EDMS
 Between versions
 ================
 .. toctree::
-    :maxdepth: 2
+    :maxdepth: 1
     
     releases/index 
     
diff --git a/docs/releases/0.12.2.rst b/docs/releases/0.12.2.rst
new file mode 100644
index 0000000000..8220786960
--- /dev/null
+++ b/docs/releases/0.12.2.rst
@@ -0,0 +1,50 @@
+================================
+Mayan EDMS v0.12.2 release notes
+================================
+
+*June 2012*
+
+This is the second maintenance release of the 0.12 series.
+
+Overview
+========
+
+
+As with the previous release bug fixes and minor feature were the focus
+for this release too.  Long standing `issue #24`_ has been fixed and document
+check outs have been added too as per the feature request posted as `issue #26`_.
+
+What's new in Mayan EDMS v0.12.2
+================================
+
+Document check outs
+~~~~~~~~~~~~~~~~~~~~~
+
+
+Upgrading from a previous version
+=================================
+
+Migrate existing database schema with::
+
+    $ ./manage.py migrate checkouts
+
+The upgrade procedure is now complete.
+
+
+Backward incompatible changes
+=============================
+* None
+
+Bugs fixed
+==========
+* `issue #24`_ "Duplicated filename extension when uploading a new version of a document"
+* `issue #26`_ "checkout feature request"
+
+Stuff removed
+=============  
+* None
+
+
+
+.. _issue #24: https://github.com/rosarior/mayan/issues/24
+.. _issue #26: https://github.com/rosarior/mayan/issues/26
diff --git a/docs/releases/index.rst b/docs/releases/index.rst
index 328b8f08cf..478e26bbd1 100644
--- a/docs/releases/index.rst
+++ b/docs/releases/index.rst
@@ -11,11 +11,12 @@ all the backwards-incompatible changes and deprecated features for
 each 'final' release from the one after your current **Mayan EDMS** version,
 up to and including the latest version.
 
-Latest version (0.12.1)
+Latest version (0.12.2)
 -----------------------
 .. toctree::
    :maxdepth: 1
 
+   0.12.2
    0.12.1
    0.12
 
diff --git a/settings.py b/settings.py
index a0da8da709..6132d57479 100644
--- a/settings.py
+++ b/settings.py
@@ -174,6 +174,7 @@ INSTALLED_APPS = (
     'main',
     'rest_api',
     'document_signatures',
+    'checkouts',
 
 # Has to be last so the other apps can register it's signals
     'signaler',
diff --git a/urls.py b/urls.py
index a6ae677f51..4f3430b786 100644
--- a/urls.py
+++ b/urls.py
@@ -32,6 +32,7 @@ urlpatterns = patterns('',
     (r'^gpg/', include('django_gpg.urls')),
     (r'^documents/signatures/', include('document_signatures.urls')),
     (r'^feedback/', include('feedback.urls')),
+    (r'^checkouts/', include('checkouts.urls')),
 )