.NET framework

[bob]

If a computer has multiple versions of the .NET framework installed,
and you launch a .NET application, what version will it use? Can you
specify to use an older version if that's what it was tested/developed
with?

 

[Pavel Minaev]

Each dotNet application has, in it's manifest, the version of the framework
it's compiled against.  As for running multiple versions of the framework on
one computer, you can run all of them and it is supported.

You can run all _major_ versions of the _runtime_ at the same time
(which are 1.0, 1.1, and 2.0), but definitely not all versions of the
framework. Keeping in mind that .NET 3.0 still has runtime v2.0, .NET
3.5 has runtime 2.0 SP1, and .NET 3.5 SP1 has runtime 2.0 SP2. So you
can't, for example, have 2.0 and 2.0 SP2 running side-by-side, nor
differentiate between them in the assembly manifest.