The search for a small Secure Shell server to fit on a laptop with 4
megs ram and no hard disk was fruitless, so Matt Johnston decided to
write his own, and Dropbear is the result.  It implements various
features of the SSH 2 protocol, including X11 and Authentication Agent
forwarding.  Dropbear is Open Source software, distributed under a
MIT-style license. It includes a server, client and tools to
generate server keys and to convert OpenSSH keys for Dropbear.

Features

    * A small memory footprint - Dropbear can compile to a 110kB
      statically linked binary with uClibc (and only minimal options
      selected).
    * Implements X11 forwarding, and authentication-agent forwarding
      for OpenSSH clients
    * Compatible with OpenSSH ~/.ssh/authorized_keys public key
      authentication
    * Features can easily be disabled when compiling to save space.
    * Preliminary TCP forwarding support (-L style only)

Homepage:
https://matt.ucc.asn.au/dropbear/dropbear.html
