I am trying to figure out how much work is involved in upgrading an existing 3.2 application to become 4.2 core compliant so I can use some debuggers out there that require this as a prerequisite. What all do i need to change - where can i get my hands on a complete list of major changes instead of pouring through the code and wondering if this is compatible or not ? I certainly don't think using the "#version 420 compatibility" in the shader isn't going to be enough.