http://forms.real.com/real/player/blackjack.html?src=serviceandsupport
They have stated that they will not port RealOne to Linux as the market is too small. Alternatively you could try wine and see if it will run RealOne on Linux.
actually, that's false - I'm downloading it right now.
1) go to http://forms.real.com/real/player/unix/unix.html 2) set OS to "Linux 2.x (libc6 i686)"; processor to "Pentium-class system"; fill out other info 3) you arrive to an "RealPlayer for Linux 2.x (libc6 i386)" (that's RP8). At the bottom of the page there's: "RealOne Player for Unix - Preview Release If you would like to try the alpha version of RealOne Player for Linux 2.2 x86, use the button below. " 4) Go to the next page through the button - Realone for Linux!
Also, the forums are here: http://realforum.real.com/cgi-bin/unixplayer/wwwthreads.pl There seems to be at least one Real guy to handle support questions and get bugs fixed.