diff --git a/SUMMARY.md b/SUMMARY.md
index fc41ab2..d635167 100644
--- a/SUMMARY.md
+++ b/SUMMARY.md
@@ -41,16 +41,7 @@
         * [ELK Stack](operating_cord/elk_stack.md)
 * [Development Guide](developer/developer.md)
     * [Getting the Source Code](developer/getting_the_code.md)
-    * [Writing Models and Synchronizers](xos/intro.md)
-        * [XOS Modeling Framework](xos/dev/xproto.md)
-            * [XOS Tool Chain (Internals)](xos/dev/xosgenx.md)
-        * [XOS Synchronizer Framework](xos/dev/synchronizers.md)
-            * [Synchronizer Design](xos/dev/sync_arch.md)
-            * [Synchronizer Implementation](xos/dev/sync_impl.md)
-            * [Synchronizer Reference](xos/dev/sync_reference.md)
-        * [Core Models](xos/core_models.md)
-        * [Security Policies](xos/security_policies.md)
-        * [Tutorial](xos/tutorials/basic_synchronizer.md)
+    * [Modeling Services](developer/xos-intro.md)
     * [Developer Workflows](developer/workflows.md)
         * [Working on R-CORD Without an OLT/ONU](developer/configuration_rcord.md)
     * [Building Docker Images](developer/imagebuilder.md)
diff --git a/developer/xos-intro.md b/developer/xos-intro.md
new file mode 100644
index 0000000..5249f3f
--- /dev/null
+++ b/developer/xos-intro.md
@@ -0,0 +1,20 @@
+# Modeling Services
+
+CORD adopts a model-based design, which is to say all aspects
+of operating and managing CORD is mediated by a model-based
+control plane. XOS is a tool that CORD uses to implement this
+control plane. For an overview of XOS, see the following white paper:
+[XOS: Modeling-as-a-Service](https://wiki.opencord.org/display/CORD/XOS+and+the+CORD+Controller?preview=/1279317/4981376/XOS%20Modeling-as-a-Service.pdf).
+
+XOS is a self-contained component of CORD, with its own
+[Guide](https://guide.xosproject.org). Consult this Guide to learn how
+to [use XOS](https://guide.xosproject.org/use.html) to write models
+and synchronizers for CORD services. The Guide also describes how
+to [install XOS](https://guide.xosproject.org/install.html) as a
+stand-alone platform, which can be useful when developing models
+and synchronizers.
+
+
+
+
+
diff --git a/operating_cord/xos_internals.md b/operating_cord/xos_internals.md
index 735e69d..03bceef 100644
--- a/operating_cord/xos_internals.md
+++ b/operating_cord/xos_internals.md
@@ -2,13 +2,9 @@
 
 XOS is the component of CORD that implements the control plane
 through which operators control and manage CORD. This normally
-happens through a set of XOS-generated interfaces:
-
-* [TOSCA](../xos-tosca/README.md)
-* [REST API](rest_apis.md)
-* [XOSSH](../xos/dev/xossh.md)
+happens through a set of XOS-generated [APIs](api.md).
 
 This section describes XOS internals, including how it is configured and
 deployed on a running POD. Additional information about how to write
 XOS models (from which these interfaces are generated) is
-described [elsewhere](../xos/README.md) in thie guide.
+described a separate [XOS Guide](https://guide.xosproject.org).