Visual Studio 2005, .NET 2.0, and C# 2.0 include a host of new features. But since your .NET 1.1 app probably runs as-is on .NET 2.0, is there any rush to load it into Visual Studio 2005 and start exploiting new .NET and C# functionality? I recently ported one of my .NET 1.1 applications to 2.0 to learn about the promise and perils of .NET 2.0—and I learned a lot more than I expected! During the port, I discovered bugs in my application that I never knew I had. I found that some programming techniques that worked flawlessly in .NET 1.1 were either partially or completely nonfunctional in .NET 2.0. And I learned which C# and Windows Forms enhancements were useful to me, and which were not. In this article, I show how you convert .NET 1.1 applications to 2.0 while taking advantage of the most compelling features in this new platform. I've included the C# Programmable Calculator, an application that I ported (available electronically; see "Resource Center," page 3) to .NET 2.0. This article and the sample application are based on the Beta 1 versions of Visual Studio 2005 and .NET 2.0. A few of the details may change as Visual Studio and the .NET platform evolve.