After living on my hard drive for a few months, I finally decided to give my new project a home: http://code.google.com/p/workhorse/ (I literally checked in the initial code today). It's very alpha right now, but the general ideas are starting to take shape.
What is WorkHorse?
WorkHorse is a BPM engine written in Java. It is meant to be both lightweight (i.e., embeddable) and powerful. By the time that I am done, I hope to prove that you don't need to force-fit BPM into BPEL, or even have a heavy-weight XML process description layer at all.
The idea for the project originated with some of the concepts/ideas in BPMN, which I like, though I recognize its weaknesses. Workflow (I am using the older, less trendy term) is a natural fit for so many types of applications, but it often seems that developers avoid it because existing solutions are too cumbersome: they force you to run them on some proprietary server, or they are simply a headache to configure and embed in your existing application.
Can WorkHorse alleviate this headache? Stay tuned.