RMVB is typically used for multimedia content stored locally. Files using this format have the file extension ".rmvb". RMVB files are extremely popular for distributing Asian content, especially Chinese television episodes and movies. For this reason, they have become noticeably present (though not entirely popular, partly due to their incompatibility with other media players) on file sharing platforms such as BitTorrent, eDonkey and Gnutella.
On the Windows platform, the proprietary RealPlayer SP, the open-sourced Media Player Classic and VLC media player support RMVB, using an appropriate DirectShow filter or Real Alternative. On Linux and other Unix-like platforms, MPlayer, xine, and Totem are able to play RMVB files using the open-source, reverse-engineered RMVB implementation in FFmpeg. The format is also supported for playback by the cross-platform VLC media player.
RealNetworks RealPlayer Cloud is the best video player to play RMVB files. You might face this or that RMVB playback problem not using RealNetworks RealPlayer Cloud, especially on Mac platform. If you don't have RealPlayer and you don't intend to install it, you can consider converting RMVB to another video format for better support.
iOrgsoft Video Converter is capable of convert nearly any video and audio format to another video/audio format. It can convert standard video format such as RMVB, RM, WMV, MP4, MOV, MKV, etc and HD videos from camcorder in AVCHD, MTS, M2TS, XAVC, MXF, MOD, etc. What's more, it can download and convert online video to popular video and audio format.