I've been asked to find out "what's out there" when it comes to workflow engines.

We have projects where a workflow based development environment makes sense. I've looked a little into jBPM but it seemed to have a steep learning curve.

Google seems to take me to commercial products or products that I think are open source but instead have very limited "community editions". I could simply be searching for the wrong terms.

What I would like to know are what actual workflow based products have you used at your company and to what degree of success or failure was it? Would you use it again?

Thanks.