It's a small, fairly unobtrusive program that eats up spare cpu cycles when your system is idle. It can be run as a screen saver if you so desire. Basically, it makes you part of a global cancer research computing grid.
I have been crunching work units for SETI for 3 years. I have done 953 units. The first 2 1/2 years my old computer took 15+ hourst to crunch. My computer I have now does one from 3 to 4 hours.
Later this year I am going to switch to something like you are showing. SETI is starting a new phase of research. I feel it is time for me to move on to something more worthwhile.