SSH Communications Security  
   Extensive information about the SSH protocol. Has a variety of SSH products for sale, including clients, servers, and VPN software.
   http://www.ssh.fi/

IETF Secure Shell (secsh) Working Group  
   Contact information and papers of a group standardizing the SSH protocol.
   http://www.ietf.org/html.charters/secsh-charter.html

SSH Master FTP Site  
   Binaries for SSH1 and SSH2 clients and servers for Windows and Unix.
   ftp://ftp.ssh.com/pub/ssh

F-Secure SSH  
   SSH clients and servers for multiple platforms. Free evaluation versions. Supports secure file copying and tunneling.
   http://www.f-secure.com/products/ssh/

The FreSSH Project  
   A free SSH1 client and server for Unix
   http://www.fressh.org/

OpenSSH for Windows  
   Minimal SSH server and client utilities for Windows which does not require full Cygwin install.
   http://lexa.mckenna.edu/sshwindows/

OpenSSH on Windows  
   Port of OpenSSH server and client for Windows.
   http://www.networksimplicity.com/openssh/

SSH Patch Repository  
   NCSA's collection of patches for SSH.
   http://www.ncsa.uiuc.edu/UserInfo/Resources/Software/SSH/patch_repository/SSH_patches.html