MKVToolNix is a collection of tools for the Matroska media container format by Moritz Bunkus including mkvmerge. The free and open source Matroska libraries and tools are available for various platforms including Linux and BSD distributions, macOS and Windows.
License: Open Source
FFmpeg is a powerful command-line tool suitable for a wide range of audio and video processing tasks, making it ideal for advanced users and automation. In contrast, MKVToolnix offers a user-friendly GUI focused on MKV file management, making it perfect for users who need to work specifically with MKV files.