May 22, 2001, 1:07 PM — If you're ever confused by, or mixed up the terms, "open source" and
"free sofware," this is for you. It's a primer on the topic of what
they are, how they are alike, and how they are different. So if
you've heard of the GPL, but are not exactly sure what it is or what
it does, this is for you. Armed with what you learn here, you will
be much less vulnerable to the veritable barrage of FUD that the
Redmondian Empire is hurling at the whole open source/free software
world.
Let's start at the top. Top down, that is. Just like structured
analysis in the corporate geek-speak of the 80's. Let's talk first
about open source. When you hear this term, do not think license.
Think development methodology. Think of source code that is widely
available. Source code that can be both viewed and changed by just
about anyone who wants to bother. That is the essence of open
source. It is "open" as opposed to "closed." It is not hidden away
in a vault like the recipe for Coca Cola, or the source code for
Windows Whatever.
Eric S. Raymond is probably the most eloquent spokesperson for the
benefits that accrue to the users of open source software. His book
"The Cathedral and The Bazaar" describes how
open source development differs from the classic software
development model. The Cathedral model, classic IT methodology, has
a small team of folks with exclusive control over the code. The
Bazaar model, describing the methodology used to develop Linux and
other successful open source/free software projects. The source
code is available to anyone who wants it, and a benevolent dictator
-- Linus Torvalds in the case of Linux -- decides what actually gets
added or changed.
Now let's talk about free software. When you hear this term, don't
think development methodology, or price, think liberty. You may
have heard the mantra "free as in speech, not free as in beer" used
to explain free software. That's because the first thing people
usually associate with free is its price. So when they hear the
term free software they think "Oh, cool. It's not going to cost me
anything." That may or may not be true, but it has nothing to do
with what makes free software free. Here are four requirements that
-- according to the Free Software Foundation -- determine whether or
not software is free:
- Users are free to use the program for any purpose.
- Users are free to examine the source code to see how it works.
- Users are free to distribute the program to others.
- Users are free to improve the program.
If a license provides all those freedoms, the FSF considers the
software covered by that license to be free software. The GPL is
not the only license which meets these criteria, there are many
others that do as well. Please note that the second and the fourth
items require access to the source code. This means that free
software must also be open source software. But the reverse is not
true, and therein lies the FUD. There are many software licenses
used with open source software which do not meet the four
requirements, and therefore software covered by them is not
considerered to be free software.
The Free Software Foundation is basically the brainchild of one man,
Richard Stallman. Stallman is known for his strong, uncompromising
ideology which views non-free software as repressive and free
software as conducive to a better, more productive society. Many
write him off as a madman, and in fact the rigidity of his beliefs
lends itself to making him an easy target for the label. But madman
or not, it is Stallman who singlehandedly has started and nurtured
the revolution which is today turning the software industry upside
down.
Stallman began the GNU (GNU
