Imagine you have two projects each featuring a different project type that requires specific tools (compiler, targets, etc...) being available on your machine. You put both projects into one solution and have all prereq's fulfilled.
So far no problem. Everything builds perfectly.
Now you have a couple of guys who don't have Toolset B e.g. However, you give them the resulting dll to link against and ask them to unload Project B from their Solution.
Also: Everything works as expected now.
Except: You now have two different solutions.
Taken for granted that there must not (!) be two solutions, is there any way to conditionally (un-)load projects from a solution on opening it, so that both environments are supported either way with only one solution file?