MKVToolnix is a software that allows you to merge and create video files with the MKV format, as well as view technical information on them.
The user interface of the program is plain and simple. You can input videos by using the file browser or the "drag and drop" method (batch processing is supported).
So, you can select and arrange tracks, chapters and tags. But you can also configure general track, format specific and extra options.
You can edit the track name, tags and timecodes, as well as select the language, default and forced track flag, and set the output filename.
Furthermore, you can change the aspect ratio, display width and height, charset, cropping, cues, compression, user-defined options, and more.
Moreover, you can add attachments and modify their name, description, MIME type and attachment style, as well as configure global options when it comes to the file or segment title and tag file.
MKVToolnix also lets you enable splitting mode (according to size, duration or timecodes), input segment UIDs, previous and next segment UID, as well as select language, charset and cue name format for each chapter. Last but not least, you can use a chapter editor, copy information to clipboard, and more.
The program takes up a low amount of system resources and contains a well-written help file. We haven't come across any issues during our tests. However, MKVToolnix could definitely use some improvements in the interface department. Otherwise, we strongly recommend it to all users.

What's New in This Release:
· mmg: bug fix: mmg will no longer print false warnings about a chapter UID not being unique. Fixes #760.
· mkvmerge, mkvpropedit, mmg: bug fix: All tools can now deal with 64bit UID values (chapter UIDs, edition UIDs etc).
· mkvmerge: new feature: If "splitting by parts" is active and the last split part has a finite end point then mkvmerge will finish muxing after the last part has been completed. Implements #768.
· mkvmerge: bug fix: The DTS and TrueHD packetizers were not flushed correctly. In some rare circumstances this could lead to mkvmerge aborting with an error message about the packet queue not being empty at the end of the muxing process. Fixes #772.
· mmg, mkvinfo's GUI, all .exes: enhancement: Added new icons by Ben Humpert based on the ones by Eduard Geier (see AUTHORS).
· mkvmerge: bug fix: Fixed handling of tracks in QuickTime/MP4 files with a constant sample size. This fixes the other reason for the "constant sample size and variable duration not supported" error. Fixes is...