[angleofrepose]

The future of coding link in the parent has a large list of similarly spirited projects. I have scattered lists of similar projects but none handy or packaged well. I'll point you to the Ink&Switch article on end user programming. https://www.inkandswitch.com/end-user-programming.html And encourage you to check out personal sites of the people involved. The lively kernel is a programming kit project that's been around in various incarnations for a long time. https://lively-next.org/ The history of Eve (also linked by that future of coding page) is rich and full of references to other projects http://witheve.com/ VPRI similarly is a gateway to lots of history on personal computing http://www.vpri.org/ of particular interest to me there is the graphical language Nile and the meta compiler Ohm. http://worrydream.com/ Bret Victor's site is another gateway you may have heard of, and the researchers at Dynamicland are also well worth exploring. More future of coding resources https://github.com/d-cook/SomethingNew

For more actual environments you can use I recommend https://observablehq.com/, https://starboard.gg/ and emacs along with the links above.