WebM is a video file format intended primarily for royalty-free use in the HTML5 video tag. The WebM Project releases WebM-related software under a BSD license and all users are granted a worldwide, non-exclusive, no-charge, royalty-free patent license. The project is sponsored by Google Inc.
The WebM container is based on a profile of Matroska. WebM initially supported VP8 video and Vorbis audio streams. In 2013 it was updated to accommodate VP9 video and Opus audio.
