diff --git a/xos/core/models/service.py b/xos/core/models/service.py
index b341e83..8373bdb 100644
--- a/xos/core/models/service.py
+++ b/xos/core/models/service.py
@@ -1,13 +1,21 @@
 import json
 from operator import attrgetter
 
-from core.models import PlCoreBase, PlCoreBaseManager, SingletonModel
+from core.models import PlCoreBase, PlCoreBaseManager, SingletonModel, XOS
 from core.models.plcorebase import StrippedCharField
 from django.db import models
 from xos.exceptions import *
 
 COARSE_KIND = "coarse"
 
+def get_xos():
+    xos = XOS.objects.all()
+
+    if xos:
+       return xos[0]
+    else:
+       return None
+
 
 class AttributeMixin(object):
     # helper for extracting things from a json-encoded
@@ -56,6 +64,32 @@
                                             None,
                                             attrname))
 
+class ServiceController(PlCoreBase):
+    xos = models.ForeignKey(XOS, related_name='servicecontrolers', help_text="Pointer to XOS", default=get_xos)
+    name = StrippedCharField(max_length=30, help_text="Service Name")
+    models_url = models.URLField(max_length=1024, help_text="URL of models.py")
+    admin_url = models.URLField(max_length=1024, help_text="URL of admin.py")
+
+class ServiceControllerResource(PlCoreBase):
+    KIND_CHOICES = (('models', 'Models'),
+                    ('admin', 'Admin'),
+                    ('django_library', 'Django Library'),
+                    ('synchronizer', 'Synchronizer Manifest'),
+                    ('rest', 'REST API'),
+                    ('tosca_custom_types', 'Tosca Custom Types'),
+                    ('tosca_resource', 'Tosca Resource'))
+
+    FORMAT_CHOICES = (('python', 'Python'),
+                      ('manifest', 'Manifest'),
+                      ('docker', 'Docker Container'))
+
+    service_controller = models.ForeignKey(ServiceController, related_name='servicecontrolerresources',
+                                help_text="The Service Controller this resource is associated with")
+
+    name = StrippedCharField(max_length=30, help_text="Object Name")
+    kind = StrippedCharField(choices=KIND_CHOICES, max_length=30)
+    format = StrippedCharField(choices=FORMAT_CHOICES, max_length=30)
+    url = models.URLField(max_length=1024, help_text="URL of resource")
 
 class Service(PlCoreBase, AttributeMixin):
     # when subclassing a service, redefine KIND to describe the new service
@@ -81,6 +115,9 @@
         max_length=30, blank=True, null=True)
     service_specific_attribute = models.TextField(blank=True, null=True)
 
+    controller = models.ForeignKey(ServiceController, related_name='services',
+                                help_text="The Service Controller this Service uses")
+
     def __init__(self, *args, **kwargs):
         # for subclasses, set the default kind appropriately
         self._meta.get_field("kind").default = self.KIND
diff --git a/xos/core/models/xosmodel.py b/xos/core/models/xosmodel.py
new file mode 100644
index 0000000..ad021d3
--- /dev/null
+++ b/xos/core/models/xosmodel.py
@@ -0,0 +1,21 @@
+import os
+from django.db import models
+from core.models import PlCoreBase
+from core.models.plcorebase import StrippedCharField
+
+# XOS: Serves as the root of the build system
+
+class XOS(PlCoreBase):
+    name = StrippedCharField(max_length=200, unique=True, help_text="Name of XOS", default="XOS")
+
+    def __unicode__(self):  return u'%s' % (self.name)
+
+    def __init__(self, *args, **kwargs):
+        super(XOS, self).__init__(*args, **kwargs)
+
+    def save(self, *args, **kwds):
+        super(XOS, self).save(*args, **kwds)
+
+#    def can_update(self, user):
+#        return user.can_update_site(self.site, allow=['tech'])
+