include links to projects i derived from

doc/index.html

@@ -59,10 +59,12 @@ in this commandline.</p>
 
 <h2>About</h2>
 
-<p>SimpleSSHD is built using parts from open source projects: dropbear
-server, openssh (for scp and sftp-server), and rsync.  Those projects in
-turn are based on other projects.  A lot of people's work is represented
-here, and very little of my own.</p>
+<p>SimpleSSHD is built using parts from open source projects:
+<a href="https://matt.ucc.asn.au/dropbear/dropbear.html">Dropbear SSH</a>,
+<a href="http://www.openssh.com/">openssh</a> (for scp and sftp-server),
+and <a href="http://rsync.samba.org/">rsync</a>.  Those projects in turn
+are built on other projects.  A lot of people's work is represented here,
+and very little of my own.</p>
 
 <p>But if you find bugs/infelicities, it's probably my fault, so email
 me:<br>