The Westmalle Tripel is indeed called the “mother of all tripels”. This type of beer was first brewed in Westmalle abbey in 1934 when the new brewing hall came into use. The current formula has stayed practically unchanged since 1956, thus more than 60 years.
This beer is generally served in 33 cl bottles, precisely the volume of the accompanying glass goblet. The bottles are sold individually, in handy packs of six or in crates of 24 bottles. And of course this beer is served in the better horeca outlets.
You can find some extra information on the website of Westmalle with some info about this beer.