Cosm is a set of protocols designed to allow computers all over the world to work together on projects. The project may be a mathematical challenge, or rendering an animation. Any large project that can be broken up into pieces and assigned to different machines.
For the Researcher: Researchers gain access to huge pools of CPU time to run their projects on. Studies can be done in a fraction of the time, theories can be proven or disproved, and since it takes hours instead of weeks, the next big development is that much closer.
For the User: Users have something for their computers to do in all their idle cycles, and get access to all the results generated by projects. You also have the opportunity to make your own projects and recruit cycles from others. It's also nice to be able to point at a project and be able to say "I helped with that".
A business gets the same advantages as everyone else, plus some of the tools like the distributed file system are very useful for operations. Businesses can also use the global pool provided they are willing to play well with others and share the results.
Cosm is the real name for the system codenamed 'v3'. [you didn't think that was really its name did you?] So if you've heard about that, then this probably is a bit familiar. A word about distributed.net.