MKVToolnix is a suite of tools to help you create, modify, and test Matroska files in Linux, Unices, and Windows. These tools perform those operations with Matroska files, as well as some other operations that OGMtools performs with OGM files.
With these tools you can get information about (mkvinfo) Matroska files, extract tracks/data (mkvextract) from Matroska files, and create (mkvmerge) Matroska files from other media files. Matroska is a new multimedia format that will become a new container format. More information about the format and its technology, extensible binary metalanguage (EBML) and at http://www.matroska.org/