- 2.0 = framework that shipped with VS 2005 VB 8.0 / C# 2.0
- 3.0 = same framework as 2.0 + WCF + WPF + WF
- 3.5 = all the above + LINQ technologies and will ship with the next
VS including VB 9.0 and C# 3.0
2.0 and 3.0 both use the 2.0 CLR (common language runtime). The only
difference is addition of Windows Communication Foundation, Windows
Presentation Foundation, and Workflow components in 3.0.
3.5 will be shipped with the next Visual Studio and the most dominent
change is the addition of LINQ (language integrated query) technologies.
There will also be new framework classes (for example, new encryption
classes designed to utilize CNG). The languages themselves will probably
have more significant changes than the framework. For a complete list of
changes, you can view the Beta documents.