I think the "gatekeeper" of Macromedia/Adobe is a bit of an overstatement; the proliferation of open SWF player projects shows it wasn't an obfuscated or challe

I think the "gatekeeper" of Macromedia/Adobe is a bit of an overstatement; the proliferation of open SWF player projects shows it wasn't an obfuscated or challenging format. Additionally, they partnered with Mozilla to write the the JS engine for Firefox, then ES4 got scrapped. Adobe, having already built and shipped it for Flash, rebranded it as ActionScript 3. But it literally was a JS engine (what was supposed to become JS, anyways) and meant to be shipped in the most "open web" browser in wide use! Also, before Atom and VS Code, Adobe worked on Brackets, which was a text editor built with web technologies (pre-Electron) with a lot of the same goals. All this to say… it still wouldn't have been my preference (I love "View Source") but there's plenty of evidence they made attempts to engage the broader developer communities and do a fair bit of work in the open.