MKVToolNix is a free application for editing MKV files. With the free app you can cut a large file into smaller pieces, or vice versa to join smaller pieces to a larger one. You can save the sound of MKV to Mp3 but also embed subtitles very easily.
It's a very practical tool for those who have HD movies on their PC and want to edit them.
The developer of MKVToolnix project Moritz Bunkus announced the release of the new MKVToolnix 14.0.0. It's a great version of open-source and cross-platform (Windows, Linux and Unix) application of MKV (Matroska).
MKVToolNix 14.0.0 "Flow" was released just one month after the release of MKVToolNix 13.0.0 "The Juggler", and seems to add a lot of new features and improvements, along with several bug fixes and some system changes.
The new MKVToolnix 14.0.0 includes support for AAC files with 960 samples per frame in mkvmerge, support for Wave64 files in the WAV reader, support for WebM files from the MKVToolNix GUI, and tag support in Mkvpropedit's WebM files. From this version, the minimum required version of Boost is 1.49.0 for the build of MKVToolNix.
The MKVToolNix GUI now has a new feature in the "Additional Modifications" dialog box, which can be used to calculate and set timeout points. Also The new MKVToolnix 14.0.0 has many bug fixes that improve AVC / H.264 and HEVC / h.265 parsers, MPEG PS and MPEG TS readers, DocBook scanner and the MKVToolnix GUI multiplex tool.