Difference between .NET framework 2.0 and .NET framework 3.0

53.

Full 64-bit support for both the x64 and the IA64 hardware platforms in 3.0

WCF, WPF, WF, Windows card space in 3.0

Support for HTTP pipelining and syndication feeds in 3.0

1 and 3

1, 2 and 3

Support for 64-bit is provided in 2.0 framework.
The major change between 2.0 and 3.0 is the new set of APIs: Windows Communication Foundation WCF - indigo in 2.0; Windows Presentation Foundation WPF - Avalon in 2.0; Windows workflow foundation WF and Windows Cardspace - infocard in 2.0. The support for HTTP pipelining and syndication feeds is provided in 3.5 framework.