LAME Now considered one of, if not THE, best MP3 encoder around, LAME started as an open source development project to improve psycho-acoustics, noise shaping, and encoding speed...FreewareDownload LAME
DivX The DivX Codec takes the power of advanced digital video compression to the next level, encoding video at resolutions up to high-definition 1920 x 1080
Play DivX videos on almost any 3rd party software media player
Achieve the perfect balance between visual quality and performance with six...FreewareDownload DivX
Mplayer MPlayer is a movie player which runs on many systems (see the documentation). It plays most MPEG/VOB, AVI, Ogg/OGM, VIVO, ASF/WMA/WMV, QT/MOV/MP4, RealMedia, Matroska, NUT, NuppelVideo, FLI, YUV4MPEG, FILM, RoQ, PVA files, supported by many native, XAnim, and Win32 DLL codecs. You can watch VideoCD...FreewareDownload Mplayer
Exaile Exaile is a media player aiming to be similar to KDE's AmaroK, but for GTK+. It incorporates many of the cool things from AmaroK like automatic fetching of album art, handling of large libraries, lyrics fetching, artist/album information...FreewareDownload Exaile
Xine Video Player xine is a free multimedia player. It plays back CDs, DVDs, and VCDs. It also decodes multimedia files like AVI, MOV, WMV, and MP3 from local disk drives, and displays multimedia streamed over the Internet...FreewareDownload Xine Video Player