[webrender]

This is already in place - by default macOS does not allow apps to be installed which do not include a signed Apple developer ID. The setting can be turned off in System Preferences.

[amake]

As of Sierra this can not be disabled in System Preferences, though there are workarounds.

[andai]

I can't believe what I just read.

[iNerdier]

What are the workarounds? I upgraded, noticed the option 'anywhere' was gone and wished I hadn't...

[amake]

I meant workarounds as in there are still ways to launch non-signed apps, like right-clicking (or ctrl-clicking, or using the Finder widget menu) the app and selecting Open.

[ricpass]

Just execute "sudo spctl --master-disable" on Terminal. And the option "Anywhere" is be available again.