netselect | Choose the fastest server automatically | Mehr ...
This is netselect, an ultrafast intelligent parallelizing binary-search implementation of "ping." You give it a (possibly very long) list of servers, and it chooses the fastest/closest one automatically. It's good for finding the fastest ftp.debian.org mirror, the least laggy IRC server, or the best Squid neighbour.
netselect-apt | Choose the fastest Debian mirror with netselect | Mehr ...
netselect-apt will choose the fastest Debian mirror by downloading the full mirror list and uses netselect to find the best one. netselect-apt writes a sources.list(5) file that can be used with apt(8).