ZDoom

BuildGDX and Eduke both have autoload folders and options to enable or disable them at the start screen. This makes loading things like texture packs or voxel packs so easy, especially in my case where I always play with some kind of upscale if they're available. I don't know how difficult this would be to implement, but it's something I'd personally love to see!

There's already several ways to autoload mods: [wiki]How_to_autoload_files[/wiki]. I believe the methods here are flexible enough to accomplish pretty much any basic autoload functionality.

The only thing really lacking in this regard is a way to disable autoloads on-the-fly, but if your needs are that specific then you really should be using a [wiki]Frontend[/wiki] launcher program like ZDL as GZDoom is probably not getting a mod loader / mod management system anytime soon.

EDIT: I'm sorry, I didn't realize this was the Raze subforum.

The problem with autoload folders is that they are unconditional. Raze supports 8 major games plus their mission packs. Having hard coded autoload folders will surely clash somewhere with that. The INI gives a lot more control over what gets loaded.