FTP

AxyFTP
X-Windows FTP client designed for Linux workstations. Motif and GTK+ versions available. Still in alpha.
http://www.wxftp.seul.org/

CrossFTP
Features, download, screenshots, purchase information, forum and support for a multi-tab GUI FTP/FXP client in Java.
http://www.crossftp.com/

Filezilla
Open Source (GNU/GPL) FTP client for Windows, Mac OS X and GNU/Linux.
http://filezilla-project.org/

IglooFTP PRO
A client for Windows and Linux (using the GTK+ library). It features drag and drop, URL clipboard monitoring, and remote directory caching.. [Windown/Linux]
http://iglooftp.com/

k.Soft Custom FTP
Custom FTP software for ISPs, portals, and web hosts, with appropriate FTP sites built-in.
http://www.ftpdesign.com/

NcFTP
Command-line client for UNIX. Includes NcFTPPut and NcFTPGet, which support FTP for shell scripts. Source code is available.
http://www.ncftp.com/ncftp/

NFTP
Text-mode FTP client for OS/2, Windows, Linux, FreeBSD, SPARC Solaris, and BeOS Intel. Offers keystroke shortcuts; quasi-GUI version available for OS/2.
http://www.ayukov.com/nftp/

Secure FTP
Package written in Java providing for secure FTP connections using SSL.
http://secureftp.glub.com/

SendFile.NET
Subscription service providing access to a browser-based Java FTP client. Includes built-in streaming file compression, works with Beehive FTP forms.
http://www.sendfile.net/