The Mythical Man-Month: Essays on Software Engineering is perhaps the single most quoted text ever written about software engineering and the project managment of large software projects. It is also one of the least implemented, prompting Brooks himself to say, "everybody quotes it, some people read it, and few people go by it." Frederick Brooks' (1931-) observations are based on his experience managing the development of OS/360, an IBM mainframe operating system.

Although the book covers many topics, Brooks' title theme, referred to as "Brooks' Law" has become the best known of his ideas. The premise of Brooks' Law is that adding manpower to a late software project just makes it later, in large part because of increasing issues with communication and their interference with project focus. Another famous statement of the law is the analogy, "Nine women can't make a baby in one month."