If yes is it as good as it can be or does it emulate it somehow ? Also do I need some kind of special sound card (maybe external interface). Thanks STAL

Not something I've been tryin' to do myself, but remembered this thread:

So far as I know this is possible, although it requires a little setting up of Reaper. The above thread should provide you with some pointers. Chiefly lacking for Reaper to become a bona-fide surround environment are surround panning controls and a surround encoder. The former may be available in the form of a plugin but I'm not sure whether Reaper supports plugin encoders to render mixes down to. That said there are external programs that will render (eg) Dolby Digital from multi-WAV or multichannel WAV. There are also some improvements that could be made to Reaper's UI and mixer to make surround mixing more intuitive (eg. a New.. template for surround and multichannel master). My feeling is that the above are all on the way, since Reaper's goal is to achieve feature parity with Logic/Cubendo and Protools. How much of a priority they are, though, is anybody's guess. z. :)

no dolby encoders yet - sony acid has one