Putting unused resources to work. Usage of computing resources that were previously invisible, unmeasurable, and untouchable. The universe is thought to consist primarily of undetected matter, called dark matter. The metaphor here is that the vast majority of computing resources are also not detectable or leveragable. For example, the majority of CPU time on most computers is not visible to the network as a whole. The SETI@home project puts some of these spare CPU cycles to work. The Swarmcast project of OpenCola puts unused bandwidth to work. The CDDB database of CD song listings puts the self interest of users who type in song listings to work by making it available for others to use, so that only one of the many owners of any particular CD should ever have to type in the song listings.