From the website of [broken link removed] Accountants:
Bean An Ti Exemption
Finance Bill 2004 provides an income tax exemption in respect of income received by persons in Gaeltacht areas under the Irish language student scheme known as Sce´im na bhFoghlaimeoirý´ Gaeilge. From the 1st January 2004 income from received from summer students is exempt from income tax. Previously a 10% tax rate applied to income earned each year from summer students in the Gaeltacht