I'm looking at deploying a Ruby On Rails app on SME7 and would like to know if it is possible to get another web server running (on top or instead of). They are making lots of good noise about Lighttpd http://www.lighttpd.net/.
Yes, it does look interesting. I've been having a play with it, and it does look nice.
Any suggestions on how to install/configure/run this inside SME (in addition to/instead of Apache)?
The easiest way to start would be for you to run it on a different port, and set up a ProxyPass entry so that apache forwards particular URLs to it. You won't need to touch the firewall that way, or break any existing apache functionality (e.g. webmail and server-manager).
Here's a run script you can use (read the developers guide to learn what a run script is and what you do with it):
[root@test7 ~]# cat /service/lighttpd/run
#! /bin/sh
exec 2>&1
exec /usr/sbin/lighttpd -D -f ./lighttpd.conf
[root@test7 ~]#