Bridge Mils

AFAIK, 'bridgemill' is most often used for one of the two possible planomill type configurations: the one where the bridge is fixed and the table moves. 

The other is sometimes called a gantry mill, or travelling-bridge mill, (occasionally 'portal' or 'travelling portal' mill) where the opposite happens. 

This tends to be more practical for really big machines- roughly half the footprint, and less mass to move.