SwitchSvnVersion created by Steve Dunn.
A command-line tool to modify Visual Studio projects. You can use to change the target platforms and target .NET Frameworks. You can also use it to target different versions of Visual Studio, e.g. from 2008 to 2010.
Released by Steve under the WTFPL license: http://sam.zoy.org/wtfpl/COPYING
Read more: GitHub