Eric Poggel (JoeCoder) has updated his open source, 3D game engine, Yage. It now has a revamped sound system that "is much more stable than the last and much better about cleaning up OpenAL resources." He has also put up a features list, where you can see what's currently implemented and what's still missing.
Eric is also looking for volunteers to contribute to the project. To that end, he has put up a list of tasks that he would like to see implemented. If nothing there strikes your fancy, you might find something on the roadmap.