Mac: Gatekeeper is a great feature in OS X that prevents applications from unidentified developers from opening up, which helps keep malware off your computer. Advanced users don't really need it though, but when you turn it off, it reenables itself after 30 days. Thankfully Terminal can solve this problem.
When you turn Gatekeeper off, it only stays off for 30 days. This can be annoying if you're the type who knows what you're doing in OS X. To disable this function, open up Terminal (Applications > Utilities) and type in the following command:
sudo defaults write /Library/Preferences/com.apple.security GKAutoRearm -bool NO
Tap Enter, then type in your password. Gatekeeper will now say disabled until you manually enable it.