I beleive .rm files are Real Media (ie, Real Player.) The rtsp:// and mms:// protocols are used by RealPlayer (like how your browser uses
http:// or
ftp://)
To view the video or audio stream, you've got two options: 1) install Mplayer, if it's not installed already. Depending on your distro, it should be on the install CDs. 2) install Real player for Linux.
If you're gonna install the Linux Real Player, here's a hint:
1) Go to this URL on the Real.com website:
http://forms.real.com/real/player/unix/unix.html
2) Enter all the neccesary details on the form. Where it says "select OS", drop down the box and choose "Linux 2.x (libc6 i386)"
3) Hit "Dowload Community Supported Player" button.
4) At the bottom of the page theres a section headed "RealOne Player for Unix - Preview Release". Click the "Download Now" button.
5) Choose your mirror and download!
The newer RealOne player is kinda hidden: If you don't set your os as "Linux 2.x (libc6 i386)" it wont give you the option to download RealOne. I had problems with the default player on this page (RealPayer 8) saying that the beta had expired, so downloading RealOne (AKA RealPlayer 10) was the only way for me to use the player.
Cheers,
Tim