Your ideas sounded very much like a mixup of Common Lisp with SLIME, Smalltalk interactivity and Unison-like storage of code in a database instead of files. I'

Your ideas sounded very much like a mixup of Common Lisp with SLIME, Smalltalk interactivity and Unison-like storage of code in a database instead of files. I've tried all of them, I think the closest thing I've seen to what you describe, which I also find very attractive, is the GT Smalltalk environment: https://gtoolkit.com/ https://gtoolkit.com/ Have you tried that? They call this idea "moldable development" as you can "mold" your environment to your needs. Even though I loved it, I ended up not using it much, mostly because it's a bit too heavy to keep handy for exploration all the time when needed (it takes like 1GB of RAM even when idle!)... as I already can do most of that with emacs, which is much lighter, I just stick with it.