The Little Brother's Database (lbdb) consists of a set of small tools which collect mail addresses from several sources and offer these addresses to the external query feature of the Mutt mail reader.
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.