Intro 2: What is DellEFI?
DellEFI is the successor to the Type11 method of installing Mac OS X on a Dell Mini 9. It is primarily a collection of drivers (extensions), bootloader software, and tweaks all wrapped up into one convenient package. In the 1.2a5 version, it now has a graphical bootloader so you can actually see which drive you are booting from. Almost all hardware is supported so far, and tweaks have been made to enable or disable features as neccessary.
Why?
Without DellEFI (and it's individual components) installation of Mac OS X would be a joke. The bootloader is necessary because Mac OS X is designed to boot from a Mac computer, which has something called EFI. There are relatively few (if any) PCs that have EFI, so we have to emulate that. The drivers (known as extensions in Mac OS X) are necessary so the Wi-Fi, audio, video, and other hardware components function correctly. And there are some settings on Macs that just aren't right for a Dell machine, so DellEFI tweaks those.
Who made DellEFI?
That's actually a really hard question to answer. The short version is that MyDellMini forum member Type11 started off the project under his name, and then when he sold his Mini the project was taken over by bmaltais and meklort, with a little help from others. The longer story is that there are a lot of components involved in the software from multiple sources. The bootloader software, Chameleon, has been around for years in various iterations, and some of the drivers were taken from other projects. Other MyDellMini forum members have contributed in testing and modifying parts of DellEFI.