WF, which stands for Workflow Foundation, was first presented in society almost six years ago on November 2007 as part of .NET 3.0. Now it comes to us as a greatly enhanced framework with polished features and some sweetness under its cape.
WF 4.5 has softened the edges that were still present in 4.0 and now offers a state machine workflow model, so we no longer have to simulate it with flowcharts or use the CodePlex state machine .
It is interesting to note that the CodePlex state machine project, which can be found at http://wf.codeplex.com/releases/view/67992, is a predecessor of the current state machine—it was put out as soon as WF4 was shipped to get feedback from the community early on.
It comes with many enhancements that the community has been asking for, such as C# expressions. The list of designer improvements is long: panning, search with navigable results, quick find, a document outline, autosurround with sequence, annotations, multiselection for activities, auto...