AFAIK the main difference is in certain provisions designed to block the use of patents to restrict the fundamental freedoms that GPL allows to the user. The main drawback is that it's incompatible with GPLv2-only software, but for new software it doesn't seem to be a problem.

Also, maybe A-GPL could be a good license here. It adds a provision that if the user accesses the code remotely (as on a server), you should share the code too. The default GPL only requires that if you distribute the binary.

PS. not a lawyer, would be happy to be corrected if something I said was wrong