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:
· mkvmerge: bug fix: Fixed mkvmerge sometimes mistakenly detecting MPEG-1 video in MPEG program streams as AVC/h.264. Fixes #845.
· mmg: new feature: When a playlist file (e.g. MPLS Blu-ray playlist) is added mmg can optionally scan all the other files in the directory that have the same extension and present the user with the results (including them playback time, total size, number of chapters, number and types of tracks). The user can then select the actual playlist file to add. The user can configure the minimum playlist duration in order to filter out too short ones.
· mmg: new feature: Added an option for disabling making the suggested output file name unique by adding a running number e.g. ' (1)'). Implements #848.
· mmg: new feature: The output file name can be auto-set to be located in the first input file's parent directory. Implements 849.
· mkvinfo, mkvpropedit, mmg's header editor: bug fix: Fixed the description for the DisplayUnit element to include value 3 "aspect ratio").
· ...