title: VS2010 Sharing Projects Between .Net Framework Versions
body: <p>I have 2 Visual Studio 2010 solutions and I need to share a project between them. However, one of the solutions needs to build against .Net 3.5 and the other against 4.0.</p>
  
  <p>If I change the Targeted Framework in one of the solutions, obviously this updates the project in the other and I can no longer compile the solution. Is there a way I can set the project to compile against different versions depending on which solution I'm using?</p>