ESPOL was a superset of ALGOL 60

ALGOL 60

ALGOL 60 is a member of the ALGOL family of computer programming languages. It gave rise to many other programming languages, including BCPL, B, Pascal, Simula, C, and many others. ALGOL 58 introduced code blocks and the begin and end pairs for delimiting them...

 that provided capabilities of what would later be known as Mohols, machine oriented high order languages, such as interrupting a processor on a multiprocessor

Multiprocessor

Computer system having two or more processing units each sharing main memory and peripherals, in order to simultaneously process programs.Sometimes the term Multiprocessor is confused with the term Multiprocessing....

 system (the Burroughs large systems were multiprocessor processor systems). It was used to write the MCP (Master Control Program)

MCP (Burroughs Large Systems)

The MCP is the proprietary operating system of the Burroughs large systems including the Unisys Clearpath/MCP systems....

 on the Burroughs B6700.

The single-pass compiler

Compiler

A compiler is a computer program that transforms source code written in a programming language into another computer language...

 for ESPOL could compile over 250 lines per second.

ESPOL was superseded by NEWP

NEWP

NEWP is a high-level programming language used on the Unisys MCP systems. The language is used to write the operating system and other system utilities, although it can also be used to write user software as well. Several constructs separate it from extended ALGOL on which it is based...

.