I would say all of them. By taking part of a discussion about the editor, they are contributing. But if you are talking about code contributions in particular. Zed has thousands of code contributors, and this discussion has hundreds of interactions, overwhelmingly supportive. There is no way for me to cross check that (but honestly I would be very surprised if there is no code contributor among the 170 upvotes this discussion got).

But this is all an aside, I was talking about contributors in a more general sense.