One of the functionalities that OSS/J TCKs need to test for is notifications. As you might know OSS/J APIs have 3 integration profiles and notifications are supported in all three profiles. Both the EJB and XML/JMS integration profile rely on JMS Topics to sent notifications from the OSS/J Server implementation to the clients that subscribed for it. For the web services integration profile JMS Topics cannot be used, WS-Notification is used Instead. Since I did not want to implement all the nitty gritty of WS-Notification myself, I searched a bit an came across Apache Muse. Now, that was a real help. Working from the wsn-consumer and wsn-producer examples that are included in the download I was able to build the WS-Notification support into the OSS/J TCK Foundation real quick. I did run into a couple of question, but the support on the user mailing list of Muse was outstanding. Using this support, I was able to resolve questions quickly and get a working implementation in no time.
In summary: two thumbs for Apache Muse!