Trappist beers are beers brewed in a Trappist monastery.
For a beer to qualify for Trappist certification, the brewery must be in or near a monastery, the monks must play a role in its production and policies and the profits from the sale must be used to support the monastery and/or social programs outside.
Only ten monasteries meet currently these qualifications, six of which are in Belgium, two in the Netherlands. Beyond saying they are mostly top-fermented, the beers produced by the Trappist have very little in common.
The current Trappist producers are:
Mont des Cats (France) has been certified, but athey produce in Chimay, they cannot use the ATP-logo
Missing from the picture: Zundert & Mont Des Cats. (They are located under respective products)