I've a list of languages, and that list has no less than four
languages called 'Pearl':
Constable, Cornell U, 80's. Constructive mathematics.
Process and Experiment Automation Real-Time Language. A real-time
language for programming process control systems, widely used
in Europe. Size and complexity exceeds Ada. DIN 66253 Teil 2,
"Programmiersprache PEARL", Beuth-Verlag, Nov. 1980.
One of five pedagogical languages based on Markov algorithms,
used in "Nonpareil, a Machine Level Machine Independent Language
for the study of Semantics", B. Higman, ULICS Intl Report No ICSI
170, U London (1968).
Brian Randell, ca 1970. Multilevel language, mentioned in
Machine Oriented Higher Level Languages, W. van der Poel,
The second one on this list the one you are referring to.
Note also that the list I'm referring to dates from January
1995. There may be more Pearls now....