The Linux desktop is shaping up to be the multimedia turf of RealNetworks. The software maker's RealPlayer digital media system will become the default tool for playing video, music and streamed Internet files on Red Hat Linux desktops, as well as on Novell's SuSE Linux desktops, the vendors announced last week.In reaction to Microsoft's emergence as the dominant media player developer, RealNetworks has taken the open source route. It recently made deals to put RealPlayer on Linux desktop systems from Sun and TurboLinux. Meanwhile, the company started development of its Helix Player, an open source media player licensed under the GPL. RealNetwork's RealPlayer 10 will be based on the Helix Player.Red Hat will put the currently-available Helix Player on its Linux-based desktops while Novell plans to put the Helix-based Real Player 10 for Linux on its SuSE-based desktops when the player is available in September of this year.In the largely Windows-based world of media players, Microsoft's Windows Media Player has around 48.1 million users in 2004, according to Nielsen Net\/Ratings, while RealNetworks has around 27.6 million.As RealNetworks moves aggressively into the Linux field, it is by no means the only open-source player for Linux. Popular Linux-based media players include Mplayer Sinek, Totem, XAnim and Xine. Check out some of the other open source media players yourself (links below) and see what you think.