The RMP extension is characteristic of files used by the program for playing RealPlayer multimedia files. An RMP is technically a text file that contains source code in a markup XML programming language. This code is interpreted by the program as a playlist, because the RMP file contains information about the set of songs to be queued in the playlist.

Since references to digital multimedia content may be location in wide area networks, RMP files are also used to share playlists on the Internet.