The ability to build workflow-enabled applications in the .NET Framework is nothing new. What is new to .NET 3.0, though, is the Windows Workflow Foundation, which gives developers greater control of workflow through functionality such as transaction support and custom activities.
Author and consultant Sahil Malik is beginning to take on WF in his blog. His first WF post offers an introduction to the technology, detailing the three styles of a workflow -- sequential, state machine or conditional -- and the three ways to write a workflow -- as pure code, as pure markup or as a bit of both.
Malik's second WF post outlines the process of creating a "Hello World" application in WF. The tutorial covers workflow basics like using drag and drop between the code and graphical views, debugging and running.
WF is currently in beta and due for release around the same time as Windows Vista. To use it with Visual Studio 2005, as Malik does in his tutorial, one needs to install WF extensions in VS 2005. Those extensions are available here.