MKV is not a natively supported video format on Windows and macOS. In addition to that, there are also free parsing and playback libraries available under the BSD license, for commercial software and hardware adoption. The source code of the libraries developed by the Matroska Development Team is licensed under GNU L-GPL. The MKV was developed as an open standards project, which means that it is open source and completely free for anyone who wants it for personal use. Streamable over the internet and local networks (HTTP, CIFS, FTP, etc).Error resilience (can recover playback even when the stream is damaged).Selectable subtitle/audio/video streams.It incorporates features you would expect from a modern container format, like: MKV container files were designed to be future proof, meaning that the files would not become outdated. USF (Universal Subtitle Format), or VobSub subtitles. For example, you could have a MKV file that contains H.264 or HEVC video codec and something like MP3 or AAC for audio codec, or. An MKV container can incorporate audio, video, and subtitles into a single file - even if those elements use different types of encoding.

MKV files are actually multimedia container formats. An MKV file, also known as Matroska Video file, is not an audio or video compression format.

Matroska codec pack+cnet