I’ve created a TextMate bundle of tools for JavaScript developers. It’s fairly small at the moment, but I might add more things as they occur to me.
I don’t know how long ago this happened, but I just noticed that gotAPI.com now has an index of Sergio Pereira’s Prototype documentation. Since it’s based on version 1.4, it’s about eight months out of date, but it’s still handy to have while we work on proper documentation. Expect an exhaustive reference when 1.5 gets a final release.