I don't really know what to do with this thing, but I want to share it.
I made a tiny little SDL-dependent joystick DLL for Game Maker as a favor for Beau Blyth. I was apalled that all these years later no one had made something for Game Maker that supported more than two gamepads.
I fixed up the library last night and noticed that since last year when I wrote it one such library has arisen; however, it's got usability issues.
Anyway. I don't know if there's a place on these forums for tools like this, which is more or less why I'm posting. Failing that, it's here as its own thread.

joydll.dll and the associated GML packs override Game Maker's default joystick functions and provide new ones which have shorter names. There are also functions for detecting button presses and releases, and detecting new or disconnected devices while the game is running. The DLL needs to be initialized and updated once per frame to work properly. It's covered under a modified Zlib license that allows free use, modification and distribution for commercial and noncommercial purposes. Also, source.
Ironically, it doesn't solve the lag bug that it was meant to fix, but it's still an improvement on any other system I'm aware of for GM.
Anyway, here it is:
http://evanbalster.com/goodies/joydll-1.1.zipI did make a topic at the GMC, but I am aware a lot of Game Maker developers avoid that place like the plague.