...Use it at http://www.net2ftp.com or install it on your own web server (PHP needed, MySQL optional).
Features: browse, copy/move/delete files and directories recursively, upload, download, edit, view code with syntax highlighting, zip and unzip.
net2ftp now also supports FTP over SSH.
Monsta FTP is a delightfully intuitive web-based file manager.
Monsta FTP is a lightweight open-source FTP client you can install on your server to manage your files through any browser, and free yourself from desktop software, forever!
ArchView is an extension of Firefox, which can open archive file online without downloading the whole archive. ArchView supports RAR and ZIP formats; HTTP, FTP and file: protocols. And it can present XUL or HTML interface.