Hi I just updated my ubuntu karmic Koala to Lucid Lynx and found sth strange on my file /etc/passwd.
Can someone tell me what it is?
As the package description says, "Realtime Kit enables realtime scheduling for the PulseAudio daemon". This is an entry for the user running the RealtimeKit daemon.
It's not actually a required package (only a recommended one):
So you can remove it (though you may find you need if your pulseaudio app doesn't sound so good afterwards - but you can just reinstall it):