SSH is used by millions of people every day to access and administer remote unix-like servers and systems > The Secure Shell Protocol (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network. Its most notable applications are remote login and command-line execution. \- via [Wikipedia](https://en.wikipedia.org/w/index.php?title=Secure_Shell) # Server Implementations The only one that really matters is [[OpenSSH]]. ## OpenSSH [[OpenSSH]] is the defacto standard implementation of the SSH protocol in use by nearly every operating system in current use. There are many downstream variants, but there are few true forks. ## Dropbear [Dropbear](https://matt.ucc.asn.au/dropbear/dropbear.html) is an important and widespread implementation used by OpenWrt and embedded systems. ## Teleport https://github.com/gravitational/teleport # Client Implementations There are many. OpenSSH's native one is the most used. With PuTTY being common on Windows. I don't know anything about the Dropbear client. # See Also - [[OpenSSH#Fish Shell Integration]] and [[git#SSH Problems]] for troubleshooting