This is not "in development" on Firefox. it's feature complete and done. Also Webkit is now working on adding this feature, which means edge is going to be DEAD LAST. Microsoft, come on. Make this happen.
Also our timeline for dropping flash is the end of 2018, because nobody wants that ******** anymore.
Our plan is to drop support for edge once we drop support for flash unless this feature is implemented. Also, it's embarrassing the only way to accomplish this right now is with an obsolete technology like Flash.
Come on MSFT. Just write this feature.
This is absolutely essential to ditch Flash. This is literally the one remaining feature preventing our site from abandoning Flash entire, and we would *love* to ditch Flash.
WebM is in development – http://dev.modern.ie/platform/status/webmcontainer/