RP are Rob Papen's initials. All the sounds in the factory set of the Virus that contain a capital RP in their names are made by him. Unfortunately there don't seem to be any demos on their site, so I don't know what it sounds like. Raymund Bayer is a who contributed a lot to the Virus adaptation for SoundDiver and made some environments for Logic. He also collects sounds by people on the net here.
Site is great fun, too.