[Haskell] STM applications and examples?

Hi Folks, I'm interested in gathering information about existing STM applications and example code that people might be working on or have lying around. It would be great to maintain a list of such applications and example code on the wiki somewhere, and use it as a resource for learning STM and research into STM implementations. If you have an application using STM, please let us know. If you can supply the code, even better. Similarly if you have some STM code that might be suitable as samples or benchmarks, we'd love to collect it. Thanks! Simon