diff --git a/docs/developer/deployments/libraries.rst b/docs/developer/deployments/libraries.rst
index cf80eab..2e60d86 100644
--- a/docs/developer/deployments/libraries.rst
+++ b/docs/developer/deployments/libraries.rst
@@ -1,7 +1,48 @@
 Libraries
 =========
-To do
+Some deployments build common functionality into libraries that may be used by
+other deployments or external applications. The following library deployments
+are currently supported:
 
+libts
+-----
+Userspace applications that depend on trusted services may use *libts* for handling
+service discovery and RPC messaging. A major benefit to application developers is
+that *libts* entirely decouples client applications from details of where a service
+provider is deployed and how to communicate with it. All TS test executables and
+tools that interact with service providers use *libts*.
+
+To facilitate test and development within a native PC environment, the *libts*
+deployment for the *linux-pc* environment integrates a set of service providers
+into the library itself. From a client application's perspective, this looks
+exactly the same as when running on a target platform with service providers
+deployed in secure processing environments. For more information, see:
+:ref:`Service Locator`.
+
+.. list-table::
+  :widths: 1 2
+  :header-rows: 0
+
+  * - Supported Environments
+    - * | *linux-pc* - service providers integrated into library
+      * | *arm-linux* - communicates with service providers in secure processing environment
+  * - Used by
+    - * Userspace applications
+
+libsp
+-----
+*libsp* provides a functional interface for using FF-A messaging and memory
+management facilities. *libsp* is used in SP deployments. For more information, see:
+:ref:`libsp`.
+
+.. list-table::
+  :widths: 1 2
+  :header-rows: 0
+
+  * - Supported Environments
+    - * | *opteesp*
+  * - Used by
+    - * Secure partitions
 
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