The .NET Framework is the easiest way to build apps on the Microsoft platform. You can download Visual Studio Express for free, and be coding in just a few minutes. You can also use the .NET SDKs and targeting packs to build apps for a given Microsoft platform, such as Windows Azure.
Red Gate Software Red Gate provides essential tools for .NET and SQL Server. Products include the industry-leading ANTS Performance Profiler, for optimizing code, and SQL Compare, for deploying database changes.