FileZilla is a free, open source FTP client. It supports FTP, SFTP, and FTPS (FTP over SSL/TLS). Filezilla runs on Windows, Linux, and Mac OS X. FileZilla was started as a computer science class project in the second week of January 2001 by Tim Kosse and two classmates. Before they started to write the code, they discussed on which licence they should release the code. They decided to make FileZilla an open-source project, because there were already many FTP clients available and they didn't think that they would sell even one copy if they made FileZilla commercial.

• The main features are the site manager, message log, file and folder view, and the transfer queue.
• The site manager allows a user to create a list of FTP sites along with their connection data, such as the port number to use, the protocol to use, and whether to use anonymous or normal logon. For normal logon, the username is saved and optionally the password.
• The message log is displayed along the top of the window. It displays the console-type output showing the commands sent by FileZilla and the remote server's responses.
• The file and folder view, displayed under the message log, provides a graphical interface for FTP. Users can navigate folders and view and alter their contents on both the local and remote machines using an Explorer-style tree interface. Users can drag and drop files between the local and remote computers.
• The transfer queue, displayed along the bottom of the window, shows the real-time status of each queued or active file transfer.
• FileZilla Server is another product. It is an FTP server supported by the same project. It supports FTP and FTP over SSL/TLS.