It's open source. Bowling and Grippo are the HW and SW engineers who produce the circuit card design and software for it. Meanwhile lots of people are tweaking the setups for this or that and contributing bits and pieces here and there. These lessons learned get wrapped up into the next generation. There are several vendors who sell the HW, but they all sell the same circuit board. There are several options while assembling the controller and there is room to do some proto circuits, but everybody is starting with the same basic board. This makes the online collaboration work, as users have some idea what other users are running and can help each other.
Since the SW is open source, you are free to make your own changes for whatever setup you can dream up, but there are so many things already wrapped into it that most people don't need to. For example, each of the outputs (to trigger relays) can be set based on almost any parameter the ECU is monitoring and even combinations of multiple parameters. So you can trigger nitrous, meth injection, fans or whatever with just the base code. It has built in functionality for lots of common ignition systems, lots of engine position inputs and so on, so you can piece together the sensors and hardware you want to run, then just configure the SW for it. Granted, the flexibility can also make it seem more complicated.
