The mythical man-month

Chapter 1: the tar pit

"Program": complete in itself, ready to be run by the author on the system on which it was developed. What we initially develop and delivers some value is normally a program.

"Programming product": can be run by anybody, in any operating environment, for many sets of data.

"Component in a programming system": works as a part of a larger product.

"A programming systems product" is a programming product and a component in a programming system. A programming systems product costs nine times the cost of a program.