"Open source software has existed for many years. But we have
only had a common definition and term for 10 years. We know this,
because it was only in April 1998 that publisher Tim O'Reilly
hosted a summit for the authors of several well-known software
packages--including GNU founder Richard Stallman, Perl author Larry
Wall, Linux creator Linus Torvalds, and Python author Guido van
Rossum. Common to all of these authors was not just the quality and
popularity of their software, but also the fact that they
distributed them free of charge, including the source code.
"O'Reilly realized that for all of their personal and
philosophical differences, there was something common to this
group, and he asked them to find common ground..."