OpenSSH provides a free version for technical users of the Internet. Although users of telnet and rlogin may not be aware that their passwords are transmitted over the Internet unencrypted they do. OpenSSH encrypts all traffic, including passwords, to prevent eavesdropping, connection hijacking and other attacks. OpenSSH also supports all versions of SSH protocols and offers secure tunneling capabilities.
The software is free but it is donationware. To support development, please consider donating.