ps3mediaserver

PS3mediaserver is a Upnp server compatible with various players (ps3, xbox 360...) that runs on Linux (it is implemented in Java) and can transcode on the fly (mencoder needs to be installed for transcoding). I can finally watch matroska videos on my XBox.
The last beta version  (1.20.409) correct an A/V synchronisation issue that the current stable version (1.10.5) has.