MKVToolNix is an open source application for working with Matroska media files. Matroska itself is a container format based on an open source standard by the non-profit Matroska organization. Matroska is a very flexible format that can contain any number of video, audio and subtitle tracks. It supports advanced features such: the latest video and audio codecs; complex chapter structures; attachments; an extensive tagging system; and comprehensive track header fields. MKVToolNix consists of multiple tools in one program: the multiplexer used to create Matroska files; the info tool for inspecting existing Matroska files on an element-by-element level; a powerful editor for chapter structures; a header editor for changing file & track headers as well as modifying attachments; and a job queue for processing long-running processes in the background. Also included are command-line programs corresponding to the tools mentioned above. These can be used as a basis for arbitrarily complex automation tasks such as batch multiplexing whole movie libraries. By buying MKVToolNix in the store you directly support the development of MKVToolNix. You will contribute to running costs such as hosting, hardware for testing purposes and acquiring standards documentation. The benefit for you is that you'll receive updates automatically without having to download & install them manually. For more information visit https://mkvtoolnix.download/