Some apps won't launch on Mavericks Since I've updated to Mavericks from Snow Leopard recently, I've noticed that some apps that I download (not from the App Store) won't launch. When I used chmod 775 on them, I could launch them. It seems some apps get wrong permissions upon downloading?

Why can't I open only certain apps, and how can I prevent it?
Mavericks has an extra security mechanism, Gatekeeper, in System Preferences->Security &amp; Privacy->General you can allow apps downloaded from: Anywhere.