The International Union for the Conservation of Nature and Natural Resources (IUCN) in the 1960's developed the first established approach in dealing with the presentation of information on rare and threatened species.
More formal IUCN Red List Categories and Criteria were developed in the early nineties to further objectively assess and prioritise species for conservation purposes at a global scale. A review of these categories and criteria was completed in 1998 and 1999 and the current version the IUCN Red list categories and criteria (Version 3.1) is now widely used around the world for species assessments (IUCN 2001). The IUCN also produce regularly updated guidelines for using the categories and criteria (IUCN 2008), and have produced guidelines for applying the criteria at a regional level (IUCN 2003).
Invertebrates
Byrne, A., Moorkens, E.A., Anderson, R., Killeen, I.J. & Regan, E.C. (2009) Ireland Red List No. 2: Non-marine Molluscs 
[11.2MB], National Parks and Wildlife Service, Department of the Environment, Heritage and Local Government, Dublin, Ireland.
Foster, G. N., Nelson, B. H. & O Connor, Á. (2009) Ireland Red List No. 1: Water beetles [7.09MB], National Parks & Wildlife Service, Department of Environment, Heritage & Local Government, Dublin, Ireland.
Fitzpatrick, U., Murray, T.E., Byrne, A., Paxton, R.J. & Brown, M.J.F. (2006) The Regional Red List of Irish Bees 2006 [576KB].
Vertebrates
Marnell, F., Kingston, N. & Looney, D. (2009) Ireland Red List No. 3: Terrestrial Mammals [3.58MB], National Parks and Wildlife Service, Department of the Environment, Heritage and Local Government, Dublin, Ireland.
Whilde, A. (1993) Irish Red Data Book 2: Vertebrates (Out of print).
Vascular Plants
Curtis, T. G. F & McGough, N. (1988) The Irish Red Data Book: 1 Vascular Plants [399KB], Wildlufe Service Ireland, The Stationery Office, Dublin.
Birds
BirdWatch Ireland and the RSPB NI have produced a list of Birds of Conservation Concern (BoCCI) in Ireland. This was updated by: Lynas, P., Newton, S.F. & Robinson, J.A. (2009) The status of birds in Ireland: an analysis of conservation concern 2008-2013. Irish Birds, 8(2): 149-166.
NPWS and the Northern Ireland Environment Agency are currently formulating All-Ireland red lists and books, which will include many more Irish species in need of conservation assessment. Red data lists and books are underway for the following groups; Fish, Moths, Butterflies, Dragonflies, Lichens, Bryophytes, and Seaweeds as well as an update of the Red list for Vascular Plants.