<a href='http://telepathy.freedesktop.org/'>Telepathy</a> is a relatively new framework abstracting the existing IM protocols such as jabber, msn, oscar. It is an API designed on top of D-Bus allowing desktop applications to easily add IM support as well as VoIP/Video capabilities.
This tutorial will explain the basic concepts behind the API. First an introduction to the specific objects used to represent connections and channels, followed by an overview of the existing components.
The second part will focus on writing a bare-bones IM client in python. This client will then be extended to support voice/video calls. Finally a simple UI will be built around this backend code.
The third part will introduce the mission-control component and how it allows any existing application to easily add support for communication code in a non-intrusive way, creating a presence-enabled desktop.