CurlAxel is a PHP class which uses curl_multithread functions to make simultaneous connections to download one file. The requests are customizable with regard to cookies, http-auth, proxy, proxy-auth, etc.
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.