WonderPop. Robert Rae <rhr@aiai.ed.ac.uk>, Edinburgh 1976. An implementation of POP for the PDP-10 that used cages for different data types. Introduced processes, properties, and some typed identifiers.
Try this search on Wikipedia, OneLook, Google
Nearby terms: WPG « WPI « WPL+ « WPOP » wps » WRAM » wrap around