Dropbear is an SSH 2 server, designed to be usable in small memory environments.
It supports: 

	* Main features of SSH 2 protocol
	* Implements X11 forwarding, and authentication-agent forwarding 
	for OpenSSH clients
	* Compatible with OpenSSH ~/.ssh/authorized_keys public key 
	authentication

WWW: http://matt.ucc.asn.au/dropbear/dropbear.html