Then RTAI might be the realtime extension of your choice! The Realtime Application Interface consists mainly of two parts:
A patch to the Linux kernel which introduces a hardware abstraction layer
A broad variety of services which make realtime programmers' lifes easier
RTAI is a true community project. Just download and try it out - the developers are looking forward to your comments, ideas and other help to make RTAI one of the best realtime extensions available!
This website is the master ressource for all kind of information about RTAI. If you feel it's interesting for you subscribe to our users' mailing list where all kinds of topics related to RTAI can be discussed.
The RTAI Team