From their homepage: "ProZilla is a download accelerator for Linux which gives you a 200% to 300% improvement in your file downloading speeds." * Supports FTP & HTTP including redirection (ProZilla & ProzGUI). * Resume Supported (ProZilla & ProzGUI). * Complete acceleration: The file will be downloaded as fast as possible as your bandwidth allows if not otherwise specified (ProZilla & ProzGUI). * Unlike certain other download accelerators available for Linux, this really works. * The number of connections that prozilla uses can be specified (ProZilla & ProzGUI). * FTPsearch support now permits fetching Mirror locations and pinging them and selecting the fastest server is automatically done (ProZilla & ProzGUI). * Downloading the same file in parts from several servers at once to increase speed (ProzGUI). Reproducible: Always App net-misc/d4x is good too, but another download manager like this one would make portage richer.
prozilla has been removed from the tree quite some time ago due to serious security issues, see Bug 70090. http://sources.gentoo.org/viewcvs.py/gentoo-x86/www-client/prozilla/?hideattic=0