http://www.citizensinformation.ie/en/employment/types_of_emp...
http://www.enterprise-ireland.com/en/Start-a-Business-in-Ire...
If you're looking to work, you need a company to sponsor you, there's a green card programme, and in practice, it's not that difficult to get in if you're a programmer with a CS degree or equivalent experience. Sure there are forms and red tape... but it's not as many hoops to jump through as moving to the US.
More info on work visas / green cards for Ireland here: http://www.citizensinformation.ie/en/employment/migrant_work...
Paperwork aside, Ireland is a fantastically beautiful country. I suggest you leave Dublin and head West to see the postcard Irish countryside. Get off the Motorways and onto the backroads. It will be well worth your while. :)
I obtained citizenship by this route in 2004 and was able to live and work in the UK with no visa requirement.