County records are coming online in Ireland every two or three months. County Limerick is the most recent to join this effort. Today the Irish Family History Foundation's Online Research Service (ORS) announced "the availability of an additional 100,000 birth, death, marriage and census records from Limerick Genealogy covering the parishes and districts of County Limerick."
Thus County Limerick joins most of the rest of Ireland in this project. In order to see if the county in which you have an interest has provided online access to its records, check out the interactive map. These records are made available on a pay as you go system where you can pay with your credit card to be able to download records. You can search for free but a nominal amount will be deducted from your deposit if you view the actual record and download it. It is similar to contacting a vital records office here and paying a small fee to get a copy of the record except the entire transaction is online.