GPL and What You Need to Know
Open Source. General Public License. Linux.
Maybe you've read about them, or maybe know somebody running something with these in the title. But maybe you haven't actually taken any more time to understand the origins of Open Source.
You've heard the buzz and know that it's transforming the IT landscape and making inroads around the globe. But maybe you need some background on what Free and Open Source Software (FOSS) is really about. And what should you know about open source licenses, such as the General Public License?
In this edition of In Focus, you'll get a brief overview of the origins of open source, some related topics to know about, and how to start making sense of the GPL
1. An Overview of FOSS
The roots of the modern Free and Open Source movement are somewhat
debatable, and their provenance is lengthy. So we'll go with an executive
summary instead. The BSD (Berkeley Software Distribution) project and its
later derivatives In and around 1984, Richard Stallman (usually referred to by his initials
RMS) founded the GNU project (GNU's not Unix) as an effort to create a
free alternative to Unix By 1991, we were up to version 2. Essentially, the GPL Free software has nothing to do with price; it's about software freedom.
The quote "Free as in Freedom not Beer" is oft-repeated in the free software
community. Free software is a philosophy and a movement that pre-dates the
term "open source" by almost 14 years.
Open Source
The term open source was coined in 1998, partially in response to a
community-driven initiative led by Bruce Perens and Eric Raymond after
Netscape released the source code for its browser (which is the roots of the
Mozilla browser and project External links to philosophy of free software and FSF:
Open Source Definition Free vs. Open Source
There are numerous differences between "free" and "open source" software.
For the free software community, a free software-compatible application is one
that offers a license that is either the GPL or is compatible with the GPL.
For the open source community, open source is software that is compatible with the open source
definition.
But in a more philosophical sense, there is a much deeper division between the
two groups.
"The fundamental difference between the two movements is in their values,
their ways of looking at the world," Richard Stallman wrote in his paper
"Free vs. Open Source Software."
"For the open source movement, the issue of
whether software should be open source is a practical question, not an
ethical one. As one person put it, 'Open source is a development methodology; free
software is a social movement.'
"For the open source movement, non-free
software is a suboptimal solution. For the free software movement, non-free
software is a social problem and free software is the solution."
The Linux Kernel
One of the things that the GNU project was missing was a kernel. A
kernel is the core of an operating system and contains much of the root
functions, such as virtual memory, multitasking, shared libraries, demand
loading, shared copy-on-write executables and TCP/IP networking.
In 1991, Linus Torvalds wrote and first published the Linux kernel. It has been
licensed under the GPL since its 0.12 release while Torvalds holds the copyright to
the Linux name. The Linux kernel is the core of the Linux operating systems and is currently at
version 2.6, though many popular distributions are running version 2.4.
One issue that has been raised in relation to the interaction of the 2.6
kernel with the 2.4 kernel is the practice of
"backporting" features of 2.6 into 2.4. Torvalds
supports the practice, saying
"it makes sense from a company standpoint to basically 'cherry-pick' stuff from the development
version that they feel is important to their customers."
Linux Kernel Issues
The origins of Linux and whether any copyrighted code was taken from Unix is
one of the issues at the root of the SCO vs. Linux controversy. (See our Special Report on the SCO/Linux controversy.)
2. What you need to know about Linux and the GPL
We asked OSDL's Open Source Architecture Specialist Bill Weinberg for a quick summary of what enterprise
users need to know about Linux and the GPL. Here are some of the highlights:
(Next: Even More Things Enterprise Users Need to Know about the GPL:)
OSI Approved Licenses
Free Software Foundation
Richard Stallman: Why Software Should Be Free
The GNU Project