Thanks for the fast and thorough response.
Never heard of Q lang (will look into it), but I've spent some time with Lua and that's pretty OK.
While 'Lil' may not be intended to be xTalk-like lang it comes close to reading like one... maybe that's an unavoidable consequence of implementing an HC-like event driven environment? Its close enough for me and has the Deck(Stack)/Card metaphor. I like it. It seem\ to have at least a subset of xTalk, but it also has list and dictionary data types, custom control widgets / contraptions, and more modern features, so that's super useful!
xTalk has the transient 'It' variable and 'The' (which is largely ignored by interpreter) which can go a long way towards making scripts read more like a natural language sentence. Being English like helps English speaking people, even very young people, learn the language fast, I know some ECL educators that will swear that xTalk is the best thing for teaching basic concepts. It is certainly what got me hooked as a kid. I also have a theory that straight readability reduces the need for as many code comments. HyperCard 2.0 had some JIT precompiling that helped speed things up, but these days it seems CPUs are fast enough to handle any extra bit of interpretation without much slowdown.
" C library might be helpful in some situation it would invariably need to be ported to and maintained as JS as well (or vice versa)"
There is the possibility of there being already ported / WASM compiled, small versions of various libraries (ImageMagick for example), but I do understand that you want/need to keep its engine small and as self-contained as possible. But then it also seems a bit pointless to maintain a Desktop app/exe versions at all, since it is still subjected to the same limitations as running sandboxed in a browser.
I think you should at least consider using 'native' file APIs for file stuff. It seems like more work to implement a System 6 file dialog from scratch then to just call out to the OS or HTML5 api. Bug report: in the built in file dialog there's no obvious way to go back up to a parent directory, Command+ArrowUp didn't work, and there's also no way to access my computers other disk partitions.
IMO one of the main things that made HC so insanely great was its extensibility with XCMDs/XFCNs. While HC couldn't play tracker formats like .s3m, .mod etc. there was an External that could enabled it. I even built MIDI librarian 'app' with HyperMIDI Xternals that could talk to my ancient Yamaha external synth modules back in to day. Lots of stuff most never would have thought you could do with HC. And HC had early polyglot coding, you could mix in AppleScript ( or any other OSA script language), via 'do feild "AppleSciptContainer"as AppleScript' syntax (which later would mean Shell commands too). If your main target is web/html5 then I think it would be great to be able to tap into JS/ HTML5 APIs (and maybe Node for the desktop version) when the need arises.
Anyway is great fun to play around with, really nice work so far!
I'll have to spend some time checking out your source later.
I also checked out your web comic. Nice, the art reminded me a bit of Cerebus the Aardvark.