BitComet Support Team's BLOG

RealMedia(RM) is a multimedia container format created by RealNetworks. Its extension is ".rm". It is typically used in conjunction with RealVideo and RealAudio and is popular for streaming content over the Internet.

Typically these streams are in CBR (constant bitrate).

Recently RealNetworks has developed a new container for VBR (variable bitrate) streams, named RMVB (RealMedia variable bitrate).

Support of RealMedia is available in a wide variety of multimedia players for different architectures/platforms, including RealPlayer and the Real Alternative codec pack.

You can use mpcstar to open files with this suffix. http://www.mpcstar.com/