of software products. WATFOR-11, -S and -11S In 1974, a compiler with characteristics similar to the IBM implementation was created for the Digital Equipment Corporation PDP-11 computer and called WATFOR-11. The team members, Jack Schueler, Jim Welch and Terry Wilkinson, were later joined by Ian McPhee who had added new control statements to the WATFIV compiler for structured programming (SP). These new statements included the block IF (later included in the ANSI X3.9-1978 language standard), WHILE, UNTIL, and others. WATFIV-S was announced in 1974 and a few months later, WATFOR-11S (the "S" indicating the new SP features) was also announced. The original SP features were later enhanced with additional statements by Bruce Hay in WATFIV-S in 1980 and by Jack Schueler in WATFOR-11S in 1981. WATFOR-77 During the 1970s, the ANSI X3J3 subcommittee (the FORTRAN language standard group) developed a new language standard which was officially approved in April, 1978. This standard, designated FORTRAN 77, introduced many new statements into the language. In fact, the previous language standard FORTRAN 66 is a very small document and describes, what is in effect, a subset of most implementations of FORTRAN. For example, the WATFIV and WATFOR-11 implementations are based upon the IBM definition of FORTRAN-IV. As programmers used the FORTRAN 77 features, a new compiler was required to combine the advantages of the WATFIV compiler with the new language standard. In January 1983, a project to develop a FORTRAN 77 compiler was started at Watcom Systems Inc. Under the leadership of Jack Schueler, Watcom employees and undergraduate students from the University of Waterloo's Co-operative Computer Science program became involved in the creation of the WATFOR-77 compiler. The major work was done by Geno Coschi, Fred Crigger, John Dahms, Jim Graham, Jack Schueler, Anthony Scian and Paul Van Oorschot. They were assisted by Rod Cremasco, John McCormick, David McKee and Brian Stecher. Many of the team members from former compiler projects provided input. These included Bruce Hay, Ian McPhee, Sandra Ward, Jim Welch and Terry Wilkinson. Unlike previous compilers, a significant portion of WATFOR-77 was written in a portable systems language to ease the implementation of the compiler on other computer systems. Earlier WATFOR compilers were written entirely in machine-dependent assembly language. Two components of the compiler are not portable. The code generator translates FORTRAN statements into native computer instructions and stores them in memory. The first version of WATFOR-77 generates instructions for