I recently discovered that OS X runs Apache on port 80 by default. I run local web servers for development on other ports but the OCD in me still couldn’t handle this. To confirm, open your favourite web browser (Chrome) and navigate to localhost. If you see It works! – read on. One terminal command will kill the process and stop it from loading on boot
sudo launchctl unload -w /System/Library/LaunchDaemons/org.apache.httpd.plist
To reverse this
sudo launchctl load -w /System/Library/LaunchDaemons/org.apache.httpd.plist