Wikipedia
Protel
Protel stands for "Procedure Oriented Type Enforcing Language". It is a programming language created by Nortel Networks and used on telecommunications switching systems such as the DMS-100. Protel-2 is the object-oriented version of Protel.
PROTEL languages were designed to meet the needs of digital telephony and is the basis of the DMS-100 line of switching systems PROTEL is a strongly typed, block-structured language which is based heavily on PASCAL and ALGOL 68 with left-to-right style of variable assignment, variable-sized arrays, and extensible structures. The designers of PROTEL significantly extended PASCAL of the day by adding external compilation and extending the data structures available in the language.