I\'m on Mac Yosemite 10.10.5. Apache web server suddenly no longer starts. I tried changing the port to 8080. Also tried sudo apachectl stop and sudo apachectl start. Still won\
After 48 hours of research, I found this working solution, I found the solution here: disable OSX's built-in Apache server.
sudo launchctl unload -w /System/Library/LaunchDaemons/org.apache.httpd.plist
This allowed XAMPP to start on 80, while POW runs on 20559.