The Big, The Small/Building Gargantuan Software; Extreme Engineering; Scientific American Presents; by Freeman; 4 Page(s)

Imagine a stack of paper the height of a 19-story building. That's what a printout of Microsoft's Windows 2000 would look like, if anyone cared to print it. With 29 million lines of code written mainly in the C++ computer language, the new operating system (OS) is by far the largest commercial software product ever built. In fact, the development of Windows 2000, and its implementation in a wide range of computer systems and locations, is arguably the most extreme feat of software engineering ever undertaken.

To understand how software could grow to such immensity, think of it not as a monolithic object but as an assemblage of snap-together blocks. There's the core OS, large enough by itself but just one part of the whole that is Windows 2000. Also bundled in are such components as an Internet browser, transaction processing (tools for updating information almost instantaneously as new data are received) and a multitude of drivers, which link peripheral devices such as printers to the OS. The drivers alone account for more than eight million lines of code, with just one of them comprising in excess of a million lines by itself.