i use CLIPS as a language for writing logic programs. Is there any Editor that supports auto-complete and other usefull IDE stuff? Thanks for Help.

You could consider emacs.

I'm not sure if it has a mode for CLIPS, but it does have many many modes, or you can make your own.

It also has a form of auto-complete which works based on looking at open buffers (or files), So if you press Alt / at any time, and you have all the possible CLIPS commands open in another buffer, then it will auto-complete from those.

Justin