A lot of people mentioned other immutable JS libraries after reading my post. I thought it would be good to make a list of available ones.
Libraries are sorted by github popularity.
Persistent Data Structures w/structural sharing
- immutable.js - Facebook's implementation with a JS-like API
- mori - ClojureScript's persistent data structures exported to JS
- ancient-oak - Not sure about this one. It doesn't seem to fully implement efficient structural sharing (tries, etc) like the above libraries, but it claims to implement parts of it and I see some implementation of a data structure in there. It also copies object props onto the data structure so you can access them like
obj.property, which is neat but might have a perf cost.