Modula-2+
Modula-2 plus exceptions and threads developed by P. Rovner et al of DEC SRC, Palo Alto CA in 1984.
["Modula-2+ User's Manual", M-C van Leunen].
["Extending Modula-2 to Build Large, Integrated Systems", P. Rovner, IEEE Software 3(6):46-57 (Nov 1986)].