FileZilla is a fast and reliable FTP client with lots of useful features and an intuitive interface.

Features:

Ability to resume Uploads/Downloads (if the server supports it)

Custom Commands - Site Manager with folders

Keep Alive system

Timeout detection

Firewall support

SOCKS4/5 and HTTP1.1 Proxy support

SSL secured connections

SFTP support - Upload/Download Queue

Drag & Drop

Multi-language support

GSS authentication and encryption using Kerberos