1. registers.nli.ie: The entire NLI collection of Roman Catholic parish register microfilms is available free to view on this site. Although it includes no searchable transcripts, the collection is presented using zoomable maps, variant parish names and date-tags, making the images much more accessible than the old microfilms. There remain serious problems with the legibility of some of the registers and the quality of some of the images.
2. FindMyPast/Ancestry.com: Because the information contained in the NLI images is not under copyright, once they appeared online the two main global commercial genealogy sites began collaboration on a full transcription. The results were published on both sites in March 2016, with FindMyPast's version free to search after registration for a free account. The underlying transcription database is identical on both sites but they each apply their own surname variants system. Search results can therefore vary considerably between the two. In addition, the poor quality of the images used for transcription (and, it has to be said, the poor quality of much of the transcription work itself) means that it is not possible to put complete faith in research in Catholic records on either site. For parts of the country where there are no other online transcripts - Wexford, Cork city, Fermanagh, some parishes in Antrim and Down - they can be used as a rough first draft of research, but a hand-search of the original images on registers.nli.ie will almost always be necessary.
Ancestry also has a completely separate set of images and transcripts from 73 parishes, in their catalogue as 'Ireland, Select Catholic Birth and Baptism Registers, 1763-1917' (dbid 6068) and 'Ireland, Select Catholic Marriage Registers, 1775-1942' (dbid 9054). These are fresh high-quality scans (and correspondingly high quality transcripts) made in the last decade as part of a parish management software package. They cover relatively few parishes and are almost all incomplete but they are orders of magnitude better than the NLI-based transcripts.
3. www.rootsireland.ie: This is the website of the Irish Family History Foundation, the umbrella body for local genealogy centres around the country. It is subscription-only and can be quite expensive but has improved tremendously from its beginnings and is now the best site for church record research.
A number of points should be kept in mind. The site does not have transcripts of all the records and is not clear enough about what is missing. Its list of Fermanagh 'baptismal' records is in fact a list of Tyrone parishes and a search reveals there are no church record transcripts of any description for Fermanagh on the site, only civil record transcripts.
There are similar problems for almost every county. The list of sources supplied by each centre and the separate drop-down list titled 'Parish/District' on the search form itself often do not match. The range of years supplied in the 'Online sources' section for each county regularly differ from the years actually searched. When using rootsireland, you need to satisfy yourself - if necessary with a series of trial-and-error queries using common surnames and wildcards - that everything the site claims to have searchable is in fact present.
However, the arrival of the NLI microfilm collection and the FindMyPast/Ancestry transcription have made it clear that the quality of rootsireland transcripts is generally very good, made as they were from the original records rather than microfilm images. The competition with the global sites also appears to have spurred improvements in service. Search results now provide a link to the corresponding NLI microfilm, if there is one. The search interface has become intuitive, relatively straightforward and quite powerful. It is possible, for example, to retrieve all baptisms marriages or burials for a particular townland without even specifying a surname. Wild cards ('%') can now be used in the 'Forename' and 'Townland / Address' boxes. It is possible even to search on godparents' names only. A recently-added forename variants option adds further to the site's search power, though the surname and forename variants system can be idiosyncratic. But no variants system can ever be relied on completely.
4. www.IrishGenealogy.ie This site is run by the Department of Arts, Heritage, Regional, Rural and Gaeltacht Affairs and originally aimed to cover areas not included by rootsireland. It has the record transcripts of two former IFHF centres, Dublin city and Co. Kerry, and its own transcripts of the Roman Catholic records of parts of Cork city, west Cork and Dublin city and the Church of Ireland records of Dublin city and Cos Carlow and Kerry. The major differences with rootsireland and FindMyPast/Ancestry are that the site is completely free and that the fresh transcripts are accompanied by images of the records, generally from NLI microfilm in the case of the Catholic records and new, high-quality colour scans in the case of the Church of Ireland records.
The basic search interface is non-standard, an attempt to be as unthreatening as possible which can cause confusion. However, with trial and error it is possible to retrieve almost everything a search could aim for. A 'More Search Options' page provides as much flexibility as possible, with wild-cards ('*') allowed in all text fields and a decent surname and forename variants system. Care should be taken not to query the site as precisely as it permits. The more exact the query terms, the less will be found. But above all, the fact that the majority of record transcripts are accompanied by images of the originals means that the most sceptical researcher can check (and correct) what the database tells them.
5. FamilySearch.org: Since the arrival of the NLI parish register site, FamilySearch has also made its copies of NLI microfilms available online. To view them, search the catalogue (familysearch.org/catalog/search ) for the parish name. Clicking on the small camera icon will open the images. A significant number of transcripts have been made from the microfilms and where such a transcript exists the search results place a small magnifying glass icon beside the camera icon. Clicking on it produces a search based on the microfilm, which can include more than the register. This is cumbersome, to say the least, but it is the only way to see precisely which parish registers have been transcribed. Otherwise the transcripts are searchable only in the vast and baggy 'Ireland Births and Baptisms, 1620-1881' collection. The site also appears to have copies of the transcripts made by Albert Casey for his monumental O'Kief Coshe, Nang series, consisting of parish registers for areas close to the Sliabh Luachra area on the Cork/Kerry border. Despite the fact that the LDS Family History Library holds close to 40% of historic Roman Catholic records on microfilm, there appears to be no concerted effort to transcribe these. 6. Other sites: Volunteers, especially in North America, have made transcripts of parish registers from LDS microfilms for areas they are researching and put them on various websites. Where there are significant numbers, these sites are noted in the county-by-county lists or the parish source lists.