Ireland is very pro entrepreneurship.

It's easy to set up a new company, the overhead is minimal and there are lots of financial and other supports available from government agencies like Enterprise Ireland:

http://www.enterprise-ireland.com/en/

We have a very low corporate tax rate and the government recently introduced R&D tax credits to encourage innovation:

http://www.bdolimerick.ie/department.php?pg=/Research%20and%...

Not to mention a very strong academic community, plenty of funding available for academic collaboration and the presence of a huge number of prominent US tech companies including Google, Facebook, Twitter, eBay, PayPal...

http://thenextweb.com/insider/2011/11/26/what-attracts-big-t...