Max Brunsfeld in fact, yep. He went along to Zed from the Atom team.

But curiously Zed hasn't been very interested in Tree-sitter. They don't seem to see it as having much strategic value to their company, which is odd because lots of other people do see it as a valuable platform. You have Tweag building code formatting on it, you had GitHub building stack graphs on it, you have Merigraph. You even have sone really "out there" stuff like the Software Evolution Library!

They use it quite a bit in Zed though. What do you count as "not very interested"?

It comes down to tree sitter being the heart of a semantic IDE. If you use Tree sitter's data to apply a fix for a formatting problem or a lint error you are making a semantic edit to your code using it: you aren't describing that change in terms of the line/col in a text buffer then, but first in terms of the path to the node you wish to adjust in the syntax tree and the semantic rules used to target it.

Zed doesn't want to build a semantic IDE. They've said it a million times, they want to build a text editor, so they just aren't going to put the tree representation at the center of the experience. A text editor's UX is built around the text buffer so that it emulates experience of coding while sitting at a typewriter filling out punch cards. We can do better than the typewriter as the anchoring metaphor for all UX!

I think those projects I listed that build on top of Tree-sitter (all ignored by Zed) all see the potential of semantic changes and of Tree-sitter as a platform for making them.

Think about it. Tree-sitter is an IDE.

I don't mean a standalone syntax highlighter, I mean it's a whole environment in which you can write software and in which things integrate. An Integrated Development Environment.

But Zed doesn't want that product. That product, if they cared that they owned it, would compete with Zed