Intercom, which is headquartered in San Francisco, was founded in 2011 by Eoghan McCabe, Des Traynor, David Barrett and Ciaran Lee. The company recently announced that it had raised $35m in Series C funding, bringing total funds raised by the company to $66m.
Originally spun out of UCD, Logentries was a provider of machine data search technology with a HQ in Boston and R&D team in Dublin.
Last month, security analytics giant Rapid7 Inc acquired Logentries for $68m, with its workforce of 70 people largely retained.
Famous for its no-frills, low-cost's and edgy marketing techniques, Ryanair revolutionized the entire airline industry spearheaded by its brash, straight-talking CEO Michael O' Leary.
Fenergo is an incredibly successful Irish financial technology start-up, with offices in Dublin, Boston and Sydney.
This summer, Fenergo completed the biggest investment round by an Irish company to date, raising €75m from Insight Venture Partners.
The biggest Irish-led start-up success story of recent years, Stripe was founded five years ago by Irish brothers Patrick and John Collison when they were just 22 and 19, respectively.