RSS means Really Simple Syndication (aka Newsfeeds). You can read them in a newsreader, like Outlook. Opera browser also supports it.
That .r21 files is probably part of a RAR arhive. It consists op multiple .rxx files. (.r01, .r02, etc). You can open any of them with WinRAR and WinRAR will extract its content.
TheMajorMMX - Intel P200 MMX @ 225Mhz - V-Tech (PcPartner) Baby-AT mb w/ Intel Triton TX chipset - Nvidia Riva TNT2 M64 w/ 16MB - 256MB M-Tec SDRAM - Still running.....