AS3 is a pretty underrated language. It was ridiculously fun to make stuff with it, and if you bought the official Flash Builder IDE (which was Eclipse based), you had decent autocomplete and everything.
The runtime definitely needed to be improved, but I feel Flash gets a bit more hate than it deserves. By the tail end, there was even decent 3D graphics support, and CrossBridge was a pretty cool predecessor to Emscripten that allowed you to convert C++ programs into SWF stuff (IIRC an early version had the Doom engine ported over).
I couldn't agree more. AS3 was my gateway drug into static typing, IDEs, all manner of things. I did have Flex/FDT at one client, but after that I ended up using Flash Develop because it was so good, even if it was Windows.
Having first MTASC and then the as3 compiler on the command line was another route into modern-day build pipelines. The 3D engines were great, Box2D port was great, and looking at it all now in 2024, the APIs still hold up and Adobe could restart an entire multimedia division with it.
The runtime definitely needed to be improved, but I feel Flash gets a bit more hate than it deserves. By the tail end, there was even decent 3D graphics support, and CrossBridge was a pretty cool predecessor to Emscripten that allowed you to convert C++ programs into SWF stuff (IIRC an early version had the Doom engine ported over).