The process command interface is more structured! You don't have to go through /bin/sh and worry about escaping. You could call exec. Ok, so you'd still have to worry about sticking "--" before the URL, but that's easy. No more worries about quoting.

Of course, chaining multiple commands together is a pain, and that's what the shell is good at, but then it is hard to get the quoting right. So a more structured shell interface. There's libpipeline, but I haven't used it to comment on.