the IBM 370 computer architecture. Most of the execution-time support (undefined variable checking, subscript evaluation, intrinsic functions) was written in assembly language for good performance. In September 1984, the first version was installed at the University of Waterloo for the Department of Computing Services. It was an implementation for IBM 370 computers running the VM/SP CMS operating system. A few months earlier, in May 1984, a project started to implement the WATFOR-77 compiler on the IBM Personal Computer. This project included Geno Coschi, Fred Crigger, Tim Galvin, Athos Kasapi, Jack Schueler, Terry Skomorowski and Brian Stecher. In April 1985, this second version of WATFOR-77 was installed at the University of Waterloo for use by students of the Faculty of Engineering. The compiler can run on a 256K IBM Personal Computer using IBM PC DOS 2.0 and does not require special floating-point hardware. In the fall of 1985, a Japanese version of WATFOR-77 was delivered to IBM Japan for the IBM JX Personal Computer. This version produces Japanese language error messages and supported the Kanji, Hiragana and Katakana character sets for variable names and character strings. To support the JX, the Language Reference manual and User's Guide were translated into Japanese. Another version of WATFOR-77 with the same features mentioned above was also developed for Japanese IBM PS/55 family of personal computers in Spring 1988. During the summer of 1986, the IBM PC version of WATFOR-77 was adapted to run on the Unisys ICON which runs the QNX operating system. Since QNX is quite different from IBM PC DOS, parts of the run-time system were rewritten. This implementation of WATFOR-77 was made available in September 1986. During the summer of 1985, a project was started to adapt WATFOR-77 to the Digital Equipment Corporation VAX computer series running the VMS operating system. The members of this project included Geno Coschi, Marc Ouellette, Jack Schueler and Terry Skomorowski. This implementation was made available in March 1987. Also, in the spring of 1988, a new project was begun to develop an optimizing FORTRAN 77 compiler. This compiler uses the code generator from the Watcom C compiler, which produces superior machine code to other C compilers. The FORTRAN 77 optimizing compiler was first shipped in mid-1990. In October 1990, the 25th anniversary of WATFOR was celebrated. Many involved in the development of the WATFOR compilers were invited to the University of Waterloo for a reunion.