The software is highly configurable so I've been designing my own race screens - mainly so we can read the key information without having to squint at the screen! You can also build up a list of drivers and a garage of cars, and it will store all the racing information for posterity. And of course, you can choose your own sounds for events, so I'll be googling for Murray Walker audio files next...
It can work with a variety of sensors including the hardware that came with Scalextric RMS and has the option of controlling all sorts of other signals through other ports - for example, it can shut off the power if you haven't refueled in time, or will control gantry lights to indicate the start of a race. These require a fair bit of wiring and a trip to Maplin, but I'd quite like to get a gantry working at some point.
All that, and it's free.