Where can I find a client program to upload my site to my web hosting ?
List of free and open-source Windows file transfer programs:
WinSCP is an open source free SFTP client and FTP client for Windows using SSH. Legacy SCP protocol is also supported. Its main function is safe copying of files between a local and a remote computer.
More info and download of WinSCP
List of free and open-source Linux file transfer programs:
gFTP is a free/open source multithreaded FTP client. It is most used on Unix-like systems and includes both a graphical and a command-line interface. gFTP is released under the terms of the GPL and has been translated into 41 languages. There is support for the FTP, HTTP, HTTPS and SFTP protocols.
More info and download of gFTP
NcFTP Client (also known as just NcFTP) is a set of free application programs implementing the File Transfer Protocol (FTP). The program has been in service on Unix systems since 1991 and is a popular alternative to the standard FTP program, /usr/bin/ftp. NcFTP offers many ease-of-use and performance enhancements over the stock ftp client
More info and download of NcFTP
List of free and open-source MacOSX file transfer programs:
Cyberduck is an open source FTP and SFTP (SSH Secure File Transfer) browser licenced under the GPL with an easy to use interface, integration with external editors and support for many MacOSX system technologies such as Spotlight, Bonjour, the Keychain and AppleScript.
More info and download of Cyberduck
Fugu is a graphical frontend to the commandline Secure File Transfer application (SFTP). SFTP is similar to FTP, but unlike FTP, the entire session is encrypted, meaning no passwords are sent in cleartext form, and is thus much less vulnerable to third-party interception. Fugu allows you to take advantage of SFTP's security without having to sacrifice the ease of use found in a graphical user interface.
More info and download of Fugu