Netcraft survey doubles surveyed sites over 2011
According to the latest report, Apache increased its market share to 65% with the largest overall growth since March. The second largest growing web server software is nginx, which now holds roughly 10% of the market. Microsoft's Internet Information Services (IIS) lost 0.15% but still has the second biggest deployment base at 14%.
You don't need to be a genius to debug a pf.conf firewall ruleset, you just need the guts to run tcpdump