.NET Framework 3.0 is the managed-code programming model for Windows, starting with Windows Vista. NET Framework 3.0 is a superset of the .NET Framework, designed to expose the new functionality in Windows Vista to the developer through managed classes. If you know how to write managed code on the .NET Framework today, NET Framework 3.0 will be familiar to you. Put another way, at PDC 2000, Microsoft debuted the .NET Framework, which introduced a new managed programming model on top of our existing Windows operating systems. With Windows Vista and NET Framework 3.0, we’re keeping that managed programming model while building new core parts of the operating system, such as moving the Windows Presentation Foundation subsystem next to GDI and User.