Comment Source control (best) or Offline Files (okay) (Score 1) 238
You have programmers. You have multiple projects. They might be working offline. For this, you really need a Distributed Source Control system such as git or mercurial. I personally recommend mercurial as it's got good Windows tools (TortoiseHg and HgScc for Visual Studio integration). You can put your "pure" repository on your share, then have the programmers push to it -- or, better yet, have an "incoming" for each project to which anyone can push, then a "pure" to which only project leads have write access and into which they can push approved versions.
If, for some reason, you simply can't run source control, Windows offers Offline Files functionality that can sync individual folders if you set them up correctly. What this means is that you need to ditch this "shared drive" concept and set up your file shares correctly -- by which I mean having multiple shares, one for each project. Users then connect to the share in question and choose to make it offline, or you create drive maps and enforce offline files using group policy.