See OpenAddresses for other OpenAddresseses
OpenAddresses.io is "a global collection of address data sources, open and free to use" which was created by OSMers User:ToeBee, User:Ingalls and User:Lxbarth, among others. In fact it started out as a spreadsheet of government address datasets maintained by ToeBee, but now has an aggregated download, an API, and a website:
github repo (and more readme description)
The data licensed CC0.
Video of a talk about OpenAddresses - A lightning talk by Alex Barth at SOTM EU 2014.