the 7040 that can deliberately set areas of memory to bad parity. When a program tries to reference variables that hadn't been set, the machine takes an interrupt (handled by the Watfor runtime routines) and the error is reported to the user as an undefined variable. This has the pleasant side effect of checking for undefined variables with essentially no CPU overhead. WATFOR quickly gained popularity and over 75 institutions installed it on their IBM 7040 systems. The distribution of the compiler was handled by Sandra Bruce (née Hope). WATFOR 360 In 1966, the University planned to replace the 7040 with an IBM System/360 computer, which was much faster but not software compatible. A team of full-time employees and undergraduate students was formed to write an IBM 360 version. The project members, Betty Schmidt, Paul Dirksen, Paul H. Cress, Lothar K. "Ned" Kesselhut, Bill Kindree and Dereck Meek, were later joined by Mike Doyle, Rod Milne, Ron Hurdal and Lynn Williams, completed 360 WATFOR in the early part of 1967. Many other institutions (universities, colleges, businesses and governmental agencies) started using the WATFOR compiler to meet needs similar to those experienced at the University of Waterloo. The distribution of the software and customer support was carried on by Sandra Ward. WATFIV As a result of proposals from the SHARE user group Fortran committee and others, a new version called WATFIV was produced in 1968. WATFIV introduced new features such as CHARACTER variables and direct-access input-output. The Association for Computing Machinery presented Paul Cress and Paul Dirksen the Grace Murray Hopper Award for contributions to the WATFOR and WATFIV projects in 1972. The WATFIV compiler was included in the DATAPRO Honour Roll for 1975 and 1976. People involved with maintenance and enhancement included Bernie Murphy, Martin Wiseman and Yvonne Johnson. WATFIV was pronounced as "WHAT FIVE", but, as was realized at the time, could also (almost) still be pronounced as "WHAT FOR", as in WAT-F-IV (Waterloo Fortran IV). Universities and corporations used these compilers and a number of other software products have been developed in the WATFOR tradition. For example, a version for the COBOL programming language is called WATBOL. Daniel D. McCracken said "it is no exaggeration to suggest that WATFOR revolutionized the use of computers in education." At one point, more than 3,000 mini and mainframe computer licenses and over 100,000 microcomputer licenses were held worldwide for this family