FileSearch is a multi-threaded documents searcher. No indexes need to be updated ; no background service is required. The more you have drives the more search speed is increased thanks to its multi-threading technic.
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.