The main goals of this project are:
To accurately document the controls a game used, using more descriptive terms. Like 270 Wheel, 380 Wheel, Throttle, etc...
To accurately document the CORRECT controls, I.E. a game uses 3 buttons instead of 4, or uses and up/down spinner instead of a trackball.
To make dealing with inconsistancies easier. 720 is this example. In the controls.dat this will always output 720 controller (or whatever we have defined for it) even if in mame it changes from dial to stick.
To relate the above controls with how they are defined/hacked into mame. This allows FE devs to accurately display control information. An example of this is the Johnny5 viewer. With this part HowardC's Viewer can read your ctrlr files and accurately display what controls you have do what in mame for a particular game.
Ok, that's straight from the fact. If you don't understand that Try, with just using mame, find all the games that require a steering wheel. Try and find out if dotron uses an up/down spinner. Try and find all the games that use 1 button and only 1 button.