VLC media player is an open source video and audio player capable of playing almost any type of media including DVDs and VCDs. In addition to being able to play most video and audio files, VLC can also post free ads without registration
File extensions that can be opened by vlc-media-player

ctx.ASX	Advanced Stream Redirector
ctx.DTS	Digital Theater Systems Audio File
ctx.GXF	General eXchange Format
ctx.M2V	MPEG-2 Video
ctx.M3U	MP3 Uniform Resource Locator
ctx.M4V	MPEG-4 Video File
ctx.MPEG1	MPEG-1 Video
ctx.MPEG2	MPEG-2 Video
ctx.MTS	AVCHD Video File
ctx.MXF	Material eXchange Format
ctx.OGM	Ogg Multimedia Container File
ctx.PLS	Playlist
ctx.BUP	DVD Information File
ctx.A52	Dolby Digital AC-3 Compressed Audio File
ctx.AAC	Advanced Audio Coding Compressed Audio File
ctx.B4S	Winamp 3+ Playlist
ctx.CUE	Cue Sheet
ctx.DIVX	DivX Movie
ctx.DV	Digital Video
ctx.FLV	Flash Video
ctx.M1V	MPEG-1 Video
ctx.M2TS	MPEG-2 Transport Stream Videos
ctx.MKV	Matroska Video Stream
ctx.MOV	Apple QuickTime Movie
ctx.MPEG4	MPEG-4 Video
ctx.OMA	OpenMG Audio File
ctx.SPX	Ogg Speex Audio File
ctx.TS	DVD Video
ctx.VLC	VLC Media Player Data
ctx.VOB	DVD Video Object
ctx.XSPF	XML Shareable Playlist Format
ctx.DAT	VCD Video
ctx.BIN	Binary DVD Video
ctx.IFO	DVD Information File
ctx.PART	Partially Downloaded File
ctx.3G2	3G Mobile Phone Video
ctx.AVI	Audio Video Interleave
ctx.MPEG	MPEG Video
ctx.MPG	MPEG Video
ctx.FLAC	Free Lossless Audio Codec Compressed Audio FIle
ctx.M4A	MPEG-4 Audio File
ctx.MP1	MPEG-1 Audio Layer I
ctx.OGG	Ogg Multimedia Container File
ctx.WAV	Waveform Audio
ctx.XM	Extended Module Audio File
ctx.3GP	3G Mobile Phone Video
ctx.SRT	DVD Subtitles File
ctx.WMV	Windows Media Video
ctx.AC3	Dolby Digital AC-3 Compressed Audio File
ctx.ASF	Advanced Systems Format Video
ctx.MOD	MOD Audio File
ctx.MP2	MPEG-1 Audio Layer II
ctx.MP3	MPEG-1 Audio Layer 3
ctx.MP4	MPEG-4 Part 14 Multimedia Container
ctx.WMA	Windows Media Audio File
ctx.MKA	Matroska Audio Stream
ctx.M4P	Protected AAC File

actx   bctx   cctx   dctx   ectx   fctx   gctx   hctx   ictx   jctx   kctx   lctx   mctx   nctx   octx   pctx   qctx   rctx   sctx   tctx   uctx   vctx   wctx   xctx   yctx   zctx   0ctx   1ctx   2ctx   3ctx   4ctx   5ctx   6ctx   7ctx   8ctx   9ctx