If you are like me, I’m sure you find yourself many times trying to remember the exact order of the arguments for a given function or even trying to guess the name of a function (was it strupper? toupper? strup?). With so many languages, it’s easy to get confused.
The interface is very good (as usual today, with a bit Ajax) and it allows you to find the function you’re stuck with in just a few seconds, a great time saver.