> Why did you need to install VS on the build servers? ... It is not needed to build web apps
VS and build servers is generally considered to be a licensing issue. But if you don't have a web app, well, you still need to build it.
We have a C++ application that uses MFC. VS is required, but not anything more than VS Express (the free edition).
"But VS Express doesn't have MFC!"
Behold: License Extensions for Visual Studio 2012 and Visual Studio 2012 SDK [1]!
> If you have a validly licensed copy of such software, you may copy and distribute the unmodified object code form of the files listed below, subject to the software's License Terms and to the additional terms or conditions (if any) that are indicated. ...
> BuildServer Files for Visual Studio 2012 Ultimate, Premium and Professional editions: ...
> All files from the following folders (and all files and folders contained within these folders, recursively) ...
> Program Files\Microsoft Visual Studio 11.0\VC\
The atlmfc folder is contained within VC. So you can install VS Express on your build server and build virtually anything with it, just copy the appropriate files.
> I know that it's needed to build some things, like unit tests that use MSTest
I am fairly sure you can do all things MSTest once you've installed the client test bits [2].
[1] http://msdn.microsoft.com/en-us/vstudio/hh857605.aspx
[2] http://www.microsoft.com/en-au/download/details.aspx?id=3818...