+Empathy is split in different processes:
+- src/empathy: contact list, considered as the main UI
+- src/empathy-chat: chat UI
+- src/empathy-call: call UI
+- src/empathy-accounts: UI to configure IM accounts
+- src/empathy-debugger: debug tool
+
+Each process can be run directly from source without having to be installed to
+its prefix. You just have to define an appropriate environment using the
+wrapper found in the tools/ directory.. For example:
+ ./tools/empathy-env ./src/empathy
+
+The chat and call UI are automatically started by telepathy-mission-control
+when receiving or requesting a chat/call. In order to use your custom version
+you have to kill any existing instance of empathy-{chat,call} and then start
+it with EMPATHY_PERSIST=1 to prevent it from auto exiting if there is no
+channel to handle. For example:
+ EMPATHY_PERSIST=1 ./tools/empathy-env ./src/empathy-chat
+
+Debugging can be turned on using EMPATHY_DEBUG=all and logged to a file
+with EMPATHY_LOGFILE=/tmp/empathy.log
+
+Sometimes you may want to load the locally compiled version of some GStreamer
+plugin (e.g. Farstream) instead of the system installed one. To do so, just
+set the GST_PLUGIN_PATH environment variable to tell GStreamer where your
+plugins are located and the GST_PLUGIN_LOADING_WHITELIST to avoid conflicts
+with system installed plugins. It's also a good idea to use GST_REGISTRY to
+avoid clobbering your default GStreamer registry. For example you can
+export these before launching the empathy processes as shown above:
+ export GST_PLUGIN_LOADING_WHITELIST=gstreamer:gst-plugins-base:gst-plugins-good:libnice:farstream:gst-plugins-bad:gst-plugins-ugly:gst-ffmpeg
+ export GST_PLUGIN_PATH=/path/to/your/custom/lib/gstreamer-0.10
+ export GST_REGISTRY=/tmp/gstreamer.registry
+