Windows Workflow Foundation 4.0 Unleashed is the definitive, comprehensive guide to WF 4.0, the powerful new workflow development framework that is exciting .NET developers around the world. Author Matt Winkler is singularly well-qualified to write this book: after nearly three years working closely with Microsoft customers as WF's technical evangelist, he is now responsible for building the tools that .NET developers will use to build WF workflows. Winkler begins by demonstrating how WF 4.0 can fit into widely diverse application architectures, how it saves time and simplifies development, and how both architects and developers can use it as effectively as possible. He thoroughly explains WF 4.0's many major improvements: enhancements that are attracting thousands of developers who chose not to adopt previous versions. Next, he drills down into more functional coverage, walking through each key task developers will need to perform with WF 4.0. Coverage includes: the runtime, control flow, activities, communications, rules, error handling, using WF Designer, hosting, migration, and much more. He also presents a full chapter on unit testing workflows: invaluable information for .N ET developers deploying WF in agile or test-driven development environments. *By Matt Winkler, formerly WF Technical Evangelist and now the Microsoft senior program manager for WF visual tooling and the WF development experience *Fully reflects the major enhancements in WF 4.0, including fundamental changes to architecture and the workflow construction process *Includes important new coverage of WF unit testing - a crucial issue for agile and TDD developers