This tweetstorm of mine[0] is relevant:
I'm sad they are killing it off. Like really, really, sad. Edge is a feat of engineering. Like operating systems, and other major browsers. These things are rare. And they're way too advanced to just kill off.
I remember IE9 being the very first browser to bet on the web being a gaming platform (not counting Flash here). Chrome was the fastest for documents/GDocs-style apps, but nothing beat IE9 in multimedia performance.
I remember learning about layout thrashing and how it causes re-paint and jank. There was an infinite zoom demo somewhere on the internet that worked by resetting width/height on wheel events. Webkit/Gecko/Presto would render it at like 2 fps. Trident? 60 fps with lots to spare.
Interactive audio, pre Audio API was impossible in all other engines. I remember they had rewritten Cut The Rope in JS, but had to use Flash for audio. Reason was, calling el.play () on a fully loaded tag was laggy on all browsers. All except IE9 of course.
I remember they did not support 3D transforms. But the 2D stuff would run the smoothest on IE9. No scaling artifacts; no aliased edges; IOW, actually usable in a multimedia setting.
You cannot have interactive content without smooth animation and responsive audio. This vision, of seeing the web as a multimedia platform, was unique to IE. As in, they were the first one actually delivering on it.
In fact, IE9 was so good, the dev team behind it so talented, it only served to show how all that talent had gone to waste all those years between IE6 and 8. (One out of many examples of financial incentive stifling talent and innovation.)
And it wasn't only technical talent either. Their developer outreach program was special. They sponsored a whole bunch of projects, from rewriting popular mobile games in JS, to original web-based experiences, showcasing what had only just then become possible to do on the web.
That outreach program showed that the open web can be more than a static platform of paper-esque documents. Rather it can be a safe medium of interactive content, allowing ever more complex ideas to be communicated. This was powerful, and inspiring.
Back to the technical side, the vast majority of innovations in EdgeHTML will never be incorporated into Blink. The architectures surely are too different. Edge's innovations will simply bitrot in a close-sourced codebase waiting to be EOLed.
I can't imagine how disappointed the team must be. Years of their best work—truly great work—thrown out. Just like that. To my fellow engineers at Edge: You all did an amazing job. And you deserved better.
Last thing I'd say even if obvious: Use Firefox. Contribute to Firefox. Tell your friends to use Firefox. You'd be fighting the monoculture, AND getting the best browsing experience out there.
[0] https://twitter.com/ariaminaei/status/1072516777937129473