It was called the Dublin United Tramway Company. The city was criss-crossed in state of the art electric trams which were powered by the most modern power station of its time out in Pidgeon House.
I am reading a book called Through Streets Broad and Narrow which is now sadly out of print. The trams offered late night services, zonal fare structure with integrated ticketing - something we still do not properly have in 2012. One of the reasons for their demise was they could not afford to convert their ticketing machines to bi-lingual as they used a symbol coded system. They also ran late night freight trains with electric locos which hauled everything from coal to rubbish.
check out the system in 1922. You could travel from Dalkey to Howth Head and from Ballymun Road to Lucan all by tram.
http://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Dublin_1922-23_Map_Suburbs_MatureTrams_wFaresTimes_Trains_EarlyBus_Canals_pub.png/795px-Dublin_1922-23_Map_Suburbs_MatureTrams_wFaresTimes_Trains_EarlyBus_Canals_pub.png
Apparently the system was the pride of Dublin until something called
Córas Iompair Éireann and replaced it with crap buses which ran when the unions felt like it.