Windows Workflow Foundation (WF) and BPEL
Once more I was asked in a Session about WF why we do use XAML and not BPEL to describe Workflows as markup. The short and simple answer from my personal point of view is: Reading the definition of BPEL, there is stated: [...] is serialized in XML, and aims to enable programming in the large. The concepts of programming in the large and programming in the small distinguish between two aspects of writing the type of long-running asynchronous processes that one typically sees in business processes. [...] AND [...] Programming in the large generally refers to the high-level state transition interactions of a process—BPEL refers to this concept as an Abstract Process [...].
XAML as used with WF focuses on specific, transformable, implementable Workflows from a developer perspective. BPEL focuses on the business perspective so it is aome abstraction levels higher than XAML. As WF will be used by future versions of BizTalk which can handle BPEL, everything can be found on the appropriate layers.
