Microsoft will add support for the WebM video format in its Microsoft Edge web browser on the PC for the upcoming Windows 10 Anniversary Update. The development of WebM, along with its VP9 video and Opus audio codecs, have been supported and championed in the past by Microsoft's rival Google.
VP9 is an efficient open source video codec developed as part of the WebM Project by Google. The VP9 and WebM project team recently joined the Alliance for Open Media effort where their work on VP9 is expected to be a significant contribution to the next generation of open-source, royalty-free video codecs. Opus was developed by the Xiph Foundation to support both bandwidth-efficient speech/RTC applications as well as high-quality media playback – all within one codec. Opus is the primary audio codec paired with VP9 in the WebM specification. We are adding support for these formats to simplify building interoperable websites, and to provide an alternative format for compressing 4K video content.
The latest Windows Insider build of Windows 10 on the PC have already included support for WebM, VP9 and Opus in Microsoft Edge.