From Just Solve the File Format Problem
VP8 is a video codec (compressed stream format) developed by Google, as a successor to various earlier-numbered VP formats (originally developed by On2 Technologies, which was acquired by Google). It is used (among other places) in the WebM container format. It is intended to be able to be used in a free and open manner, with Google pledging free licensing of its related patents. VP9 was later released as a successor to it.