An ALGOL superset with high level instructions for low level actions, e.g. interrupting another processor on a multiprocessor system. Its single pass compiler was very fast: over 250 lines/s on a 10MHz processor.
ESPOL was used to write the MCP (Master Control Program) on the Burroughs 6700. It was superseded by NEWP.
["The B6700 ESPOL Reference Manual", Burroughs, 1970].