MKVToolNix is a free application for editing MKV files. With the free app you can cut a large file into smaller comeyea, or vice versa to join smaller pieces into a larger one. You can save MKV audio to Mp3 and also embed subtitles very easily.
It is a very practical one tool for those who have HD movies on their computer and want to edit them. 
The developer of MKVToolnix project Moritz Bunkus announced the release of the new MKVToolnix 15.0.0. It is a large version of it open-source and cross-platform (Windows, Linux and Unix) application of MKV (Matroska).
MKVToolNix 15.0.0 "Duel with the Devil" was released just one month after the release of MKVToolNix 14.0.0 "Flow", and seems to add a lot of new features and improvements, along with several bug fixes and some system changes.
The new MKVToolnix 15.0.0 comes with a new much more practical GUI that supports editing its color attributes video.
You can see all changes from release notes and of course to
download the application to the platform you want
