And ruffle-rs[2] is a reimplemenation of the flash player itself in Rust. (So you'd still be using ActionScript for authoring)
[1]https://www.openfl.org/ [2]https://github.com/ruffle-rs/ruffle
The first beginner tutorial is about displaying a bitmap and starts with a terminal [1]. This is not as discoverable as Flash’s tools, which felt more like MS Paint when first opened.
[1] https://www.openfl.org/learn/haxelib/tutorials/displaying-a-...
But why reinvent the wheel? I think that the key to Flash's success is in its roots as an excellent, intuitive vector graphics editor called SmartSketch. (Way easier to use than Inkscape, IMO) They added animation to compete with Macromedia Shockwave in 1995, and the rest is the well known history of corporate greed and a victim of its own success.
The Flash IDE is still around, however (https://www.adobe.com/products/animate.html), but Adobe's giving it up at the end of 2020 :( I can only hope that they open source it.
A light, friendly version is Flash 5. It's available online (http://www.oldversion.com/windows/macromedia-flash-5-0), weighs in at a whopping 18 MB, and still works on Windows 10!
Anyway, Flash 5 Player .swf files can be exported as standalone .exe "Projectors". For example, the IDE tutorial one (https://www.sharhon.com/files/flash5test.exe) stands at 405 KB and still runs on Windows 10 as well. Surely it would be possible to wrap _real_ Flash projectors in a WebAssembly Windows NT emulator using a drag-and-drop webpage...and let the games begin.
The Flash IDE, now called Animate, continues to be developed by Adobe. They have not announced an end of life for this tool. It will still be updated after 2020. In fact, it can now export a variety of new formats other than SWF files for Flash Player, and they've been expanding the animation features quite a bit in recent years.
It's unfortunate that many people are confused about what exactly Adobe has discontinued. So many people in this thread are lamenting that this user friendly animation tool no longer exists as a starting point for new users, when in fact, it does and will still be in active development beyond 2020.
(AS1 is gone too, it was something you had to write by selecting verbs in a massive dropdown, and good riddance to that.)
Animate really isn't as simple to use as Flash is, and bluntly in the modern Era the CC suite is too expensive to get those young users.
I wonder if Affinity will have a go at this in the long run.
There is a workflow you can use with a custom Adobe Animate plugin that lets you use Adobe Animate as your authoring tool.