I just solved an issue I had installing the software drivers for the Canon p150 Scanner, where I was getting the error that it was unable to install the package since the developer was not identified. I'm using Mac OSS Mavericks on a Macbook Air 2013.
Simple fix -- went into System Preferences under Security and Privacy, General tab, then select the "allow apps to be downloaded from "Anywhere". I just tried to upload a screenshot but upload image was greyed out for some reason.
Software package then installed perfectly.