Why is the size of .NET Framework 4.0 installer smaller than 3.0/3.5?

Question

As I can see, beta2 of .Net Framework 4.0 installation program is only 55MB, and it was 200+MB for .Net 3.5, What's happening?

Answer 1

.NET 3.5 size is that big because it contains the x64 version of the framework in the same package. The 2.0, 3.0 packages were separated for x86 vs x64. I guess 4.0 will adopt a separated approach too. This link explains it: link

Answer 2

This follow on from the work done to optimise the framework for the Silverlight plug-in.

.net is now 10 years old, new techniques and just some good old fashioned spring cleaning of the code is before performed on version 4, to (hopefully) give us a sharper, more refined and more capable framework with the new version.