Differences Between WF Rules Engine and the BRE Included With BizTalk

Got to spend some time here at TechReady reviewing Windows Workflow Foundation (WF) and specifically, the business rules functionality embedded. Microsoft Business Rules BMOC Jurgen Willis did a great session explaining the rules framework built into WF. Some differences between the Microsoft Business Rules Engine (that ships with BizTalk Server) and the Rules Engine that ships with WF that I observed (and that you can infer from the existing WF beta) ...

• WF rules don't have the concept of vocabularies, which exist in the BRE
• The rules in WF allow for an "else" condition, unlike the BRE where you usually set up conditions, and then negation conditions
• There is no real concept of versioning in the WF rulesets. The only versioning that you do is assembly based. BRE rulesets are versioned and natively reside in a physical data store
• The BRE has long-term facts used by the engine, while WF rules don't really have that concept
• The WF rules engine does not use a Rete-based algorithm, unlike the BRE which does. This is done because human workflow based rules benefit from the alternate algorithm.
• Remember that the BRE offers many infrastructure/management features that WF does not. For instance, native persistence store, a business-friendly design environment, tracking and analysis of rules, and a scalable hosting service.