This is an implementation/demo of collaborative text editing via operational transforms. It's mostly inspired by Daniel Spiewak's description of operational transform.

Originally, I implemented the seminal (though, unfortunately incorrect) Concurrency Control in Groupware Systems by Ellis & Gibbs from 1989. You can see that (unsuccessful) implementation in my commit history. Don't look too closely :)

This implementation includes transformation/composition of operations, generation of operations based on text changes, and application of operations to text. In addition, it includes all the logic necessary for handling communication and conflict resolution between multiple clients over an out-of-order high-latency network.

The test coverage is reasonably complete. I still have to add tests for inferring operations from changed text (i.e. testing SimpleTextInferrer) & adjusting cursor locations based on operations (i.e. testing SimpleCursorApplier).

I found the use of FlowType invaluable for my sanity while working on this project.