Thank you for the information.
Yes, we saw it. lighttpd is a very small web server almost as fast as litespeed. But it has no web admin interface, no throttling and connection accounting, no proxy, limited configurability, ...
The implementation of its claimed features is very simple, which lacks flexibilites that you can find on Apache or Litespeed.
Litespeed is looking forward to covering 95% Apache's features but in a much faster manner. It probably not the case for lighttpd, the author probably just want to keep it as light as possible.