phpAnti-Leech is a php anti-leeching script which features a flexible configuration file and many features that put it ahead of some commercial software. This script has IP download limiting, download logging, directory masking, and resuming.
QT based Linux web security tool that it is designed to test targets for weak passwords using crack, leech and URL testing functions. Plugins allow potentially any protocol (eg http, ftp) or server to be attacked, while remaining anonymous using proxys.