why does OSX 10.9 decline permission to run software that is says comes from "an unknown source"?
I have tried to install a couple of apps and keep getting a no can do message like
iMac, Mac OS X (10.7.5), Safari 6.0.4
See the heading "How to open an app from a unidentified developer" on this support page. The instructions apply to installer packages and other installable items as well as applications.