EU money and lots of it
I vote EU money.
when they separated from britain they got 'compensation' money iirc and then they joined the EU and got more money
Now why do I have an inkling that there's a wee bit of jealousy involved here? Are you guys uncomfortable with the Irish managing to upset the natural order of the universe according to Great Britain?

EU subsidies by itself don't do the trick. *Cough. Greece, Southern Italy. Cough* What did it, was the Irish realizing what a fantastic asset being a low-wage, English-speaking country with full access to the Common European market was. Ask Micro$oft about it.
It were the Irish themselves who had the good sense to seize the opportunity their position offered them.

Celtic Tiger.