we have developed an utility project referenced by many other projects developed in sharepoint 2010. Now we are starting to use sharepoint 2013 and would like to still use the methods present in that utility. They should all be compatible with the new version, and I know I could create a copy of the current project change the referenced dll to make it work.
But that would make me replicate any change in one of the utilities in the other one. Is there a way to develop once and be able to run in both versions?