Microsoft recently donated the StockTrader source code to a new Apache incubation project called Stonehenge.  Kamal Bath is coordinating Microsoft's participation and recently posted on the project here.

We think this is potentially a big deal because:

a) it’s our first time to be a code contributor to Apache

b) we see this as a great way to foster interoperability testing on WS-* where any customer or vendor can propose test cases and the results are openly published for all to see (because of Apache’s strong adherence to principles of openness in their processes).

While this project has a lot of potential, what it really needs is active participants and contributors.  If you have an interest in web services interoperability, and especially if you have experience or interest in open source projects, I encourage you to check Stonehenge out and get involved.