Not having the source code sucks, but it's not a showstopper ; some videogame preservation websites have managed to workaround this issue.

It's possible to play "Prince of Persia" in the browser (through DOSBOX recompiled to Javascript).

It's even possible to play the original Windows 95 (!) Pinball in the browser. Seeing the Windows 95 cloudy boot sequence in a Javascript canvas is disturbing. The game isn't as smooth as native, but it's definitely playable. ( https://classicreload.com/win9x-3d-pinball-space-cadet.html )

The opcode’s were documented, and tools like Haxe do compile to swf. There is a lot of information available about the scripting part, but indeed it would be a great task. However I can’t wait to compile some C++ code using FlasCC [1] and run that in a wasm player.

[1] https://labs.adobe.com/technologies/alchemy/

Yeah, if I remember right they couldn't open source parts of it because some parts had other licenses in it. I'm recalling (but I could be wrong) that they wanted to in 2011 or so... but couldn't because of that. Don't remember the source though.

> The attempts at building something compatible like shumway have all been rather unsuccessful.

Alternative proprietary implementation was rather successful for game development. Sadly Scaleform GFx is now discontinued too and obviously we'll never see Autodesk publish anything under open source license.

I wish Adobe would start making publications though, they know Flash has been end-of-life for ages yet there's a lot of earlier internet media still in that format.

Flash is now Animate.

> I don't think Adobe ever open-sourced the Flash codebase, right?

This shows we should only allow technologies on the web if they have a clear path to preservation.

I think a similar thing should hold for DRM'ed video. Such videos may be supported on the web, but we should demand they lose their DRM when their copyright expires.