This is NASM - the famous Netwide Assembler. Back at SourceForge and in intensive development! Downloads on this page may be out of date. Get the current versions from http://www.nasm.us/.
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.