How this might look like from a configuration perspective. Changes OpenSimDefaults.ini.

OpenSim/Capabilities/Caps.cs

@@ -85,6 +85,7 @@ namespace OpenSim.Framework.Capabilities
         public string CapsObjectPath { get { return m_capsObjectPath; } }
 
         private CapsHandlers m_capsHandlers;
+        private Dictionary<string, string> m_externalCapsHandlers;
 
         private static readonly string m_requestPath = "0000/";
         // private static readonly string m_mapLayerPath = "0001/";
@@ -167,6 +168,7 @@ namespace OpenSim.Framework.Capabilities
             m_agentID = agent;
             m_dumpAssetsToFile = dumpAssetsToFile;
             m_capsHandlers = new CapsHandlers(httpServer, httpListen, httpPort, (httpServer == null) ? false : httpServer.UseSSL);
+            m_externalCapsHandlers = new Dictionary<string, string>();
             m_regionName = regionName;
         }
 
@@ -266,6 +268,17 @@ namespace OpenSim.Framework.Capabilities
             //m_log.DebugFormat("[CAPS]: Registering handler for \"{0}\": path {1}", capName, handler.Path);
         }
 
+        /// <summary>
+        /// Register an external handler. The service for this capability is somewhere else
+        /// given by the URL.
+        /// </summary>
+        /// <param name="capsName"></param>
+        /// <param name="url"></param>
+        public void RegisterHandler(string capsName, string url)
+        {
+            m_externalCapsHandlers.Add(capsName, url);
+        }
+
         /// <summary>
         /// Remove all CAPS service handlers.
         ///

bin/OpenSimDefaults.ini

@@ -408,6 +408,65 @@
     ;
     ;DisableFacelights = "false"
 
+[ClientStack.LindenCaps]
+	Cap_AttachmentResources = "localhost"
+    Cap_AvatarPickerSearch = "localhost"
+    Cap_ChatSessionRequest = "localhost"
+    Cap_CopyInventoryFromNotecard = "localhost"
+    Cap_DispatchRegionInfo = "localhost"
+    Cap_EstateChangeInfo = "localhost"
+    Cap_EventQueueGet = "localhost"
+    Cap_FetchInventory = "localhost"
+    Cap_ObjectMedia = "localhost"
+    Cap_ObjectMediaNavigate = "localhost"
+    Cap_FetchLib = "localhost"
+    Cap_FetchLibDescendents = "localhost"
+    Cap_GetDisplayNames = "localhost"
+    Cap_GetTexture = "localhost"
+    Cap_GetMesh = "localhost"
+    Cap_GetObjectCost = "localhost"
+    Cap_GetObjectPhysicsData = "localhost"
+    Cap_GroupProposalBallot = "localhost"
+    Cap_HomeLocation = "localhost"
+    Cap_LandResources = "localhost"
+    Cap_MapLayer = "localhost"
+    Cap_MapLayerGod = "localhost"
+    Cap_NewFileAgentInventory = "localhost"
+    Cap_NewFileAgentInventoryVariablePrice = "localhost"
+    Cap_ObjectAdd = "localhost"
+    Cap_ParcelPropertiesUpdate = "localhost"
+    Cap_ParcelMediaURLFilterList = "localhost"
+    Cap_ParcelNavigateMedia = "localhost"
+    Cap_ParcelVoiceInfoRequest = "localhost"
+    Cap_ProductInfoRequest = "localhost"
+    Cap_ProvisionVoiceAccountRequest = "localhost"
+    Cap_RemoteParcelRequest = "localhost"
+    Cap_RequestTextureDownload = "localhost"
+    Cap_SearchStatRequest = "localhost"
+    Cap_SearchStatTracking = "localhost"
+    Cap_SendPostcard = "localhost"
+    Cap_SendUserReport = "localhost"
+    Cap_SendUserReportWithScreenshot = "localhost"
+    Cap_ServerReleaseNotes = "localhost"
+    Cap_SimConsole = "localhost"
+    Cap_SimulatorFeatures = "localhost"
+    Cap_SetDisplayName = "localhost"
+    Cap_StartGroupProposal = "localhost"
+    Cap_TextureStats = "localhost"
+    Cap_UntrustedSimulatorMessage = "localhost"
+    Cap_UpdateAgentInformation = "localhost"
+    Cap_UpdateAgentLanguage = "localhost"
+    Cap_UpdateGestureAgentInventory = "localhost"
+    Cap_UpdateNotecardAgentInventory = "localhost"
+    Cap_UpdateScriptAgent = "localhost"
+    Cap_UpdateGestureTaskInventory = "localhost"
+    Cap_UpdateNotecardTaskInventory = "localhost"
+    Cap_UpdateScriptTask = "localhost"
+    Cap_UploadBakedTexture = "localhost"
+    Cap_UploadObjectAsset = "localhost"
+    Cap_ViewerStartAuction = "localhost"
+    Cap_ViewerStats = "localhost"
+    Cap_WebFetchInventoryDescendents = "localhost"
 
 [Chat]
     ; Controls whether the chat module is enabled.  Default is true.