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.
Medusa provides a framework for implementing asynchronous socket-based servers for TCP/IP, and on Unix, Unix domain sockets. The first release includes HTTP, FTP, and 'monitor' (remote python interpreter) servers. Medusa can simultaneously support several instances of either the same or different server types - for example you could start up two HTTP servers, an FTP server, and a monitor server. Then you could connect to the monitor server to control and manipulate medusa while it is running.
GNOME Commander is a fast and powerful graphical file manager. It has a "two-pane" interface in the tradition of Norton and Midnight Commander. It features drag'n'drop, GNOME MIME types, FTP, SFTP, and WebDAV using the GnomeVFS FTP module, SAMBA access, the ability to extend the context menu with entries to call external applications or scripts on the selected items, quick device access buttons with automatic mounting and unmounting, a fast file viewer for text and images, a history of recently accessed folders, and folder bookmarks.
FTP Rider is a collection of Python scripts that build an FTP search engine. Only path/filenames are indexed, not the contents of the files. The indexer recursively follows all directories. It indexes multiple FTP servers concurrently (default is 50), and the information is stored in a MySQL database.