GetSmart is a download manager that supports Multi-Connection downloads. With Multi-Mirror search it can download different parts from these mirror servers simultaneously. It can 'act as proxy' to serve multiple clients. It can also works as a Daemon.
Download Catalyst is a multi-platform download manager that accelerates and resumes downloads resursively using concurrent threads, with an extensible API & multiple planned UIs (both console and GUI). Besides HTTP/FTP, it also supports proxy connections