w32codec-all-2006 is the most important codec pack for Linux, used by many media players, including Xine and Mplayer.

Most important video codecs:

· MPEG-1 (VCD) and MPEG-2 (SVCD/DVD/DVB) video
· MPEG-4 in all variants including DivX ;-), OpenDivX (DivX4), DivX 5 (Pro), XviD
· Windows Media Video 7/8 (WMV1/2)
· Windows Media Video 9 (WMV3) (using x86 DLL)
· RealVideo 1.0, 2.0 (G2)
· RealVideo 3.0 (RP8), 4.0 (RP9) (using Real libraries)
· Sorenson v1/v3 (SVQ1/SVQ3), Cinepak, RPZA and other QuickTime codecs
· DV video
· 3ivx
· Intel Indeo3 (3.1, 3.2)
· Intel Indeo 4.1 and 5.0 (using x86 DLL or XAnim codecs)
· VIVO 1.0, 2.0, I263 and other H.263(+) variants (using x86 DLL)
· MJPEG, AVID, VCR2, ASV2 and other hardware formats
· FLI/FLC
· HuffYUV
· various old simple RLE-like formats

Most important audio codecs:

· MPEG layer 1, 2, and 3 (MP3) audio
· AC3/A52 (Dolby Digital) audio (software or SP/DIF)
· AAC (MPEG-4 audio)
· WMA (DivX Audio) v1, v2
· WMA 9 (WMAv3), Voxware audio, ACELP.net etc (using x86 DLLs)
· RealAudio: COOK, SIPRO, ATRAC3 (using Real libraries)
· RealAudio: DNET and older codecs
· QuickTime: Qclp, Q-Design QDMC/QDM2, MACE 3/6 (using QT libraries), ALAC
· Ogg Vorbis audio
· VIVO audio (g723, Vivo Siren) (using x86 DLL)
· alaw/ulaw, (ms)gsm, pcm, *adpcm and other simple old audio formats