Small-scale ECSE research. The program synthesizer, undertaken in the early 1970s, was the forerunner of the programming environments that are in use in most modern software engineering projects today, and yet it was performed at a scale of perhaps six to seven person-years (one faculty member and one graduate student) with total funding of about $150,000 over its lifetime.

Medium-scale ECSE research. The Sprite operating system, described in Chapter 1, was undertaken in the 1970s. It lasted four to five years, involved two full-time-equivalent faculty and several graduate students, and consumed perhaps $1 million over its entire lifetime.

Large-scale ECSE research. The Multics project was a large-scale systems research project undertaken in the 1960s to develop a scalable time-shared computer utility. Over its eight-year R&D lifetime, its ARPA-supported budget was on the order of $2 million per year; in addition, the Bell Telephone Laboratories and General Electric (later Honeywell) contributed comparable resources during this period. At MIT the development effort in addition to staff involved about a dozen faculty members and perhaps two dozen graduate students. Although commercialization of Multics was only moderately successful—a peak of 77 sites worldwide—concepts researched and developed through the Multics project (such as virtual memory, mapped files, dynamic linking, protection mechanisms) play key roles in many operating systems today. The UNIX operating system in particular built heavily on the Multics experience.