Free PHP Web Based FTP Client
phpWebFTP offers a way of connecting to you FTP server, even when you are behind a firewall or proxy not allowing traffic to FTP servers. This is very common in business networks. phpWebFTP overcomes this issue by making a FTP connection from your webserver to your FTP server and transfering the files from this web server to your webclient over the standard http protocol. phpWebFTP is free software and the source is available under GNU license.