"No one would buy a car with the hood welded shut, but that is essentially what commercial software is. However, since computing began, some software has been distributed in such a way that users can change or repair it by modifying its source code--the step-by-step instructions that the computer executes when the software runs. Software distributed under a license that allows a programmer to modify the source code and freely distribute an improved version of it is called open source.
"Open-source software can make good business sense. For example, a company might be able to reduce costs by building a product on top of an existing open-source application rather than writing it from scratch..."