Ogg Media File
The Xiph.Org Foundation developed a open standard container format for the streaming and manipulation of digital multimedia.
The format can contain audio, Metadata,Text and video streamy and play them at the same time.
One of the advantages of OGG is that it is free and not restricted by Patents so the various codes contained in OGG are supported by many media players both commercial and non commercial.
OGG also supports lossless and lossy compression.
How to open .ogm files?
Software to open .ogm files
What are .ogm files