It's not the GUI that's the problem. The difficulty comes when you pull/fetch-merge and somebody has pushed a change in a file you're editing. Binary files aren

It's not the GUI that's the problem. The difficulty comes when you pull/fetch-merge and somebody has pushed a change in a file you're editing. Binary files aren't easy to merge, so now you're going to lose your changes, or they're going to lose theirs. This is the problem the check in/check out (lock/unlock, whatever) mechanism is designed to solve. It gets in your way a bit when working on files that could be automatically merged, but it's completely necessary when working on files that can't. A system like perforce stores the files read-only on disk, and makes them writeable when you check them out. To do that you visit the perforce GUI and try to check the file out; if somebody else has the file checked out already, the server will tell you who it is, so you can go and talk to them and decide how you're going to order the edits. (Because of the read-only flag, even if you don't check out at least the files you know you'll need before you start work (which you should do), you at least find out immediately when you try to save. So even if you then end up losing a bit of work - it happens - you at least won't get too far into your work before finding this out.)