Hyper Estraier is a full-text search system. It works as with Google, but based on peer-to-peer architecture. Using Hyper Estraier, we can construct a large-scaled search engine with cheap computers.
Open source project that offer summary and download services on this page is a project that carry out their development work on other open source development sites. Their work is linked to this page via a feature called OFI, and their work is not carried out here on OSDN site.