Acid-State for haskell (http://acid-state.seize.it/) is based on a similar ideology and in the public domain. (Oh, but minus the time dimension I'm afraid.)
Acid-State is quite different, it persists representations of operations to disk (to make it durable) and keeps the data structure in memory.
I'm working on a project to bring persistent data-structures to disk ( https://github.com/DanielWaterworth/Siege ). It's currently undergoing a rethink, hence the lack of recent activity, but it's still in development.
I'm working on a project to bring persistent data-structures to disk ( https://github.com/DanielWaterworth/Siege ). It's currently undergoing a rethink, hence the lack of recent activity, but it's still in development.