Workflow Engines and Products

I am in love with workflow products, workflow engines in particular. Listed below are some of workflow engines and workflow based(*) products that I came across and looked at over last 3 years.

BPM
* Tibco iProcess
* BizTalk
* Savvion
* Lombardi
* Oracle BPEL Process Manager

Other Products
* IBM Tivoli Intelligent Orchestrator
* JOpera
* Full Armor Workflow Studio
* K2.Net
* LogicBase Harmony
* Skelta
* Adobe LifeCycle Workflow
* Opalis - oh I know this engine well
* overview pdf
* Taverna
* TurboWorx - look ma, they lost their domain! Oh, don't even think of going torboworx dot com ...

Workflow Engines
* YAWL
* Bossa
* OpenWFE
* Enhydra Shark
* ActiveBPEL
* Windows Workflow Foundation

Hords of open source Java engines are listed here and here (with discussion). Interestingly, there is no open source C++ workflow engine. I googled hard, but only found a dead one in C. I'll be happy if you proves me wrong.

Here you could imagine me doing a product review. But let's save your time and cut straight to the bottom line.

Over last 10 years everyone and his brother had been building a workflow engine. Most of the products listed have their own ones. Developing them has been a lot of fun. This time is over. Now in 2007 workflow engine becomes a commodity. Who are the leaders?

I nominate ActiveBPEL and WinWF