AxY FTP (formerly known as WXftp) is an easy-to-use FTP client for the X Window System. Features include an intuitive user interface (Motif and GTK+), side-by-side local and remote directory listings, simple and convenient session manager, on-line help, progress bar, passive and non-passive transfers, and more.
BetaFTPD is a single-threaded FTP daemon. The single-threadedness makes it faster than most other FTP daemons (contrary to common belief), and makes it extremely light on memory. Although it lacks a few functions (which you probably won't miss), the current version is very small and has a decent amount of functionality. BetaFTPD is built on the concept of heavy code reuse, which should hopefully make it easier for other programmers to contribute.
bftpd is a very configurable Linux FTP server which can do chroot without special configuration or directory preparation. It will work out-of-the-box with almost no configuration required, and works on all Unix variants tested. Most FTP commands are supported, and user authentication is done via passwd/shadow or PAM. tar/gzip on-the-fly is supported.
curl and libcurl is a tool for transferring files using URL syntax. It supports HTTP, HTTPS, FTP, FTPS, SCP, SFTP, TFTP, DICT, TELNET, LDAP, POP3, IMAP, SMTP, RTSP, RTMP, and FILE, as well as HTTP-post, HTTP-put, cookies, FTP upload, resumed transfers, passwords, port numbers, SSL certificates, Kerberos, and proxies. It is powered by libcurl, the client-side URL transfer library. There are bindings to libcurl for about 40 languages and environments.
DeleGate is a multi-purpose application level gateway or proxy server that mediates communication of various protocols, applying cache and conversion for mediated data, controlling access from clients, and routing toward servers. It translates protocols between clients and servers, converting between IPv4 and IPv6, applying SSL (TLS) to arbitrary protocols, merging several servers into a single server view with aliasing and filtering. It can be used as a simple origin server for some protocols (HTTP, FTP, and NNTP).
The ECLiPt Mirroring Tool is a full featured FTP mirror script written in Python. It supports nice config files, many features for controlling the mirror (include, exclude of files, special watermarks for deleting files, download just the latest version of some program), as well as producing nice HTML output.
EFTP is a backwards-compatible server and client which implement an extension to the FTP protocol. The extension provides protocol-level support for directory recursion and compression over a persistent connection. As would be expected, for the extension to be used, the extended client must be connecting to an extended server.