ProFTPD is a proven, high-performance, scalable FTP server written from scratch, with a focus toward simplicity, security, and ease of configuration. Naturally, ProFTPD powers some of the largest sites on the Internet. It features a very Apache-like configuration syntax, modules, and a highly customizable server infrastructure, including support for multiple 'virtual' FTP servers, anonymous FTP, and permission-based directory visibility.
FSP is a UDP-based protocol for transferring files. It has many benefits over FTP, mainly for running anonymous archives. It is usable on lines with high packet loss ratio (70% WiFi), can go behind firewalls and unnoticed by port scans (because of UDP), does not overload networks when hosting ISOs or movies, share files on modem lines without eating all of the bandwidth, and keeps lamers away from your site (they don't know how to get to it). This project is active continuation of the FSP code base (abandoned 1996-2003).
JFileUpload is a Java applet that allows uploading of files and folders to any Web or FTP server. This component can be integrated into any application, whether the server-side technology is JSP/Servlet, PHP, Coldfusion, CGI, or Microsoft ASP. The front-end provides an upload progress bar, a cancel button, and drag-and-drop support. JFileUpload supports very large uploads over 2GB and can resume broken uploads. Its colors, size, and language can be customized.
Secure FTP Factory is a set of Java classes for communicating with FTP servers using the FTP, SFTP (FTP over SSH), and FTPS (FTP over SSL) protocols. The components offer complete FTP functionality, including the ability to transfer files, rename files, delete files, create directories, transfer directories recursively, and more.