Server was running a home-baked version of lighttpd because of reasons that no longer apply.
After updating lighttpd using yum, it refuses to start:
$ service lighttpd start
Starting lighttpd: 2009-02-09 18:13:55: (plugin.c.417) plugin-version doesn't match lighttpd-version for fastcgi
2009-02-09 18:13:55: (server.c.859) Initialization of plugins failed. Going down.