(Not to be confused with Telepathy-Qt4, the high-level binding maintained by the Telepathy project.)
telepathy-qt, also known as QtTelepathy, is a Qt4 package from the Tapioca project, containing base classes for use in connection managers, and proxy classes for use in clients. It's used in at least TapiocaQt. However, it's not up to date with current developments in the Telepathy specification (the last available version supports telepathy-spec 0.13).
The current version is in svn: svn co https://svn.sourceforge.net/svnroot/tapioca-voip/trunk/telepathy-qt