That's the other thing. Version control is tricky with image-based systems. I won't say impossible, I never looked deeply into what Smalltalk/Pharo folks are doing, but since between playing with Pharo and Glamorous Toolkit I saw Git being integrated first-class into one of them, I imagine someone has some idea how to deal with the problem.

What I meant though isn't collaborative/historical tracking, I meant day-to-day ergonomics; closer to "drastically different view on what 'undo' means", except it doesn't even have to be 'undo' - I don't need the ability to rollback every single thing; I just want to know whatever the hell I actually did an hour ago when I quickly SET-VALUE and IGNOREd my way through a few random condition popups and evaluated some code in between. Being careful and keeping track of this as I go slows me down and is kind of the opposite of REPL-driven interactive development ideas; nah, I should be able to go fast now, and later be able to review all the random surgery I did on a live image.

EDIT:

> undotree on neovim allows this because it offers a drastically different view on what "undo" means

As I understand it, this "different view" is treating undo history as a tree? If so, I know this from Emacs via similarly named `undo-tree' package. But honestly, the moment I saw this I thought this is brain-dead stupid most obvious way of treating undos. It's very unfortunate that almost no software embraces this approach, instead opting for a linear history that gets trimmed the moment you undo a few steps and make a change.

If you want to see a truly different view of undo, check out what Emacs does by default. I don't even understand it fully, but best I can tell after studying the explainer in undo-tree's documentation, is that Emacs is using a linear history like everyone else, but instead of moving back through the history and discarding "the future" when you branch out, `undo' itself is an undoable operation that gets appended to undo history, so when you type some things, undo it, type something else, and keep pressing undo, you'll erase the last text, then "undo the undo" and end up with the first thing you typed...