rm RealNetworks, an internet streaming Media Company, is credited as the developers and owners of the proprietary RealMedia multimedia container format. The filename extension .rm refers to this format which is used as an audio and video wrapper to distribute digital media content over the internet. The first version of this container was released in 1997 and has been popularized for its ability to unpack the digital stream while it is being downloaded over computer networks such as the internet. The format is platform agnostic and works equally well on Microsoft Windows as it does on Linux or Mac OS.
wav The Waveform Audio file format associated with the .wav filename extension was a format developed through collaboration between Microsoft and IBM. It is an extension of the RIFF and was first released in 1991. It is one of the earliest standards used for encoding audio bit streams on personal computers. It is typically used for storing uncompressed raw audio files on the Microsoft Windows platform, however it enjoys cross platform support on Macintosh and Linux and does have support for compressed audio. Because of the relatively large file sizes of uncompressed .wav files, the WAVE format in unpopular for file distribution over limited bandwidth computer networks including the internet.