This is a simple HTTP server for serving static files.  It is suitable
as a lightweight replacement for full-fledged HTTP servers on sites
where only sporadic serving of static data is needed.

One of such use cases is deployment of Let's Encrypt certificates on a
server that runs only proxy software, such as Pound or HAProxy.  In this
case using e.g. Apache or even Lighttpd just to serve Let's Encrypt
challenge requests arriving once every 90 days is clearly an overkill.