Real Networks has released their Real Player for Linux. Unfortunately, many users had problems setting it up. When running an older kernel, you may need to disable the 16bits sound playback. When running the Linux kernel 2.2 with Real Player 5.0, you may need to use a workaround to get the Real Player to work. The workaround is available from the Web.
Real Networks provides the Real Player for Linux and for RedHat Linux. The RedHat Linux version comes in the RPM format. Here it is: