The free databases include:
- Atlases, Maps and Reference Materials - An Hibernian Atlas
- Census, Tax and Voters Lists - Protestant Housekeepers in Counties Antrim, Derry, Donegal, and Londonderry, Ireland — 1740
- Church Records - Index to the Marriage Licence Bonds Diocese of Cloyne, Ireland
- Newspapers and Periodicals - The Search for Missing Friends in the Boston Pilot
- Societies and Organizations - Charitable Irish Society of Boston
The website doesn't say how long the databases will remain free. It only says "for a limited time", so you might want to head on over soon.