Especially as demand for video grew, the web needed a next-generation codec to make high-quality streaming faster and more reliable. H.265 promised efficiency gains, but there was no guarantee of another OpenH.264-style arrangement. The risk was another fragmented ecosystem where browsers like Firefox couldn’t play large portions of the web’s video.

To solve this, Mozilla joined other technical leaders to form the Alliance for Open Media (AOM) in 2015 and started ambitious work on a next-generation codec built from Google’s VP9, Mozilla’s Daala, and Cisco’s Thor.