I was in a similar situation last spring and really didn't find anything that worked. But that was pre-Google Wave. Today, I believe the open-sourced wave ref

I was in a similar situation last spring and really didn't find anything that worked. But that was pre-Google Wave. Today, I believe the open-sourced wave reference server (http://code.google.com/p/wave-protocol/ http://code.google.com/p/wave-protocol/) includes op trans. It's under Apache 2.0 and I doubt it'd take you long to rip out and wrap op trans into something useful for you. FYI, after failing to find anything last year, I ended up implementing an operational transformation framework from scratch (using standard comet for comm). The literature's good enough that you can make sense of it all. Solo, it took me 2 weeks to implement the algorithm, another 2 weeks to put a callback framework around it to make it useful (like a SAX parser for changes to a shared xml structured document) and one more week to port it to js (original in Java) and add networking. Was a ton of fun and even useful for a couple of projects (shared canvas, text editor, collaborative UML'ing).