Suppose I wanted to create an open source Windows Forms project written in .NET. I am pretty well-established in my opinion that the System.Windows.Forms suck big time. I love Developer Express' controls, but they cost an arm and a leg and I don't see how their per-developer licensing would make it possible to use them on an open source project.
What options are there for third-party Windows Forms controls to be used in an open source project? I don't care whether the controls themselves are open source - just that they have good functionality and look good.