By default, you can right click anything from anywhere and choose "Open". It will install/run, and you will never be asked about that program again. But you have to make a conscious decision to run it.
Gatekeeper was on for appstore and signed applications and I had to disable it to install something I downloaded (ironically because OS X told me to - X11).
Gatekeeper was on for appstore and signed applications and I had to disable it to install something I downloaded (ironically because OS X told me to - X11).