In addition, it's what Linus chose for Linux in order that those who follow can have access to his creation. But what I love about the GPL is the same thing that Microsoft and other corporate predators hate about it: it works.
What does it protect?
As explained on the GNU/FSF website, the definition of "free software" encompasses four separate freedoms. None of these freedoms have to do with the price of beer. The four freedoms are:
- The freedom to run the program, for any purpose (freedom 0).
- The freedom to study how the program works, and adapt it to your needs (freedom 1). Access to the source code is a precondition for this.
- The freedom to redistribute copies so you can help your neighbor (freedom 2).
- The freedom to improve the program, and release your improvements to the public, so that the whole community benefits (freedom 3). Access to the source code is a precondition for this.
Fine. You may be thinking, "I can do that already with software that's in the public domain, or covered by other open source licenses, like the BSD-style license." You're right, you can. But software in the public domain, and software covered by a BSD-style license, is not afforded any protection whatsoever to ensure those same freedoms exist for the next user, or the next, or the one after her.
How does it work?
The GPL makes those freedoms self-perpetuating by requiring that anyone who obtains and redistributes GPLd software to release it under the same terms. This is sometimes referred to in a pejorative sense as its "viral nature." Call it what you will, this feature is what provides the protection for the four freedoms. This is what provides Linus -- and thousands of other free software authors -- the protection they want for their software.
Microsoft, for example, took the BSD-licensed TCP/IP stack from the public and swallowed it up in its proprietary product line. Then sold back to the public what it had taken from them. Legally, of course. The BSD-style license offers no protection against that sort of thing.
They've done the same thing with Kerberos, except worse. They made their version of Kerberos work fully only with their servers. Public pressure forced them to provide documentation for their closed-fisted proprietary pirated version, but they attached a restrictive license to the documentation which made it impossible for it to be used in free software.
Once again, it was piracy of public software. Stolen in order to increase Bill Gates' personal fortune. But it was legal theft. The MIT license covering Kerberos provided no protection against that sort of thing.
I love the GPL because it protects Linux and other great software from falling into the clutches of the real software pirates.
How well does it work?
The Linux kernel is the poster-boy for GPLd software. It's become the little OS who could, the bumblebee who could fly, the impossible notion that a bunch of kids on the Internet could create the most successful operating system in history come true. All of that has happened at least partly because of the GPL.
Linux thrives for several reasons, but chief among them them is its community of developers, a community unrivaled by any other platform. Are they drawn to Linux by a charismatic leader? Some, no doubt. To my way of thinking, Linus Torvalds' greatest genius is not in code, but in creating an environment where many gifted coders can work together for the common good. But don't forget, in his heart of hearts, Torvalds is a geek: a sub-species not noted for being warm and fuzzy people-persons.
Could it be the license? For many, yes. The GPL is often described as idealistic and altruistic. If the kernel developers were interested only in the code, wouldn't the BSDs be the ones with the huge development corps instead of Linux? That's what we're told all the time by the BSD-bigots, it's better technically.
But they are not just interested in the code. The GPL adds a magic glue to the Linux community, the good feeling that comes from doing good for others, and knowing that it will continue to do that good for as long as it is used. If you don't know what I'm talking about, then you are probably never going to "get it" as far as the GPL, or Linux, is concerned.
The GPL covers a whole lot more than just the Linux kernel. Check the statistics. Freshmeat.net lists almost 36,000 projects covered by more than 50 different licenses. The page showing percentage covered by specific license reveals over 68% of those projects are licensed by the GPL. What's in second place? The GPL's sibling license, the GNU Lesser GPL, with nearly a 6% share. Coming in third, with 3.57%, is the original BSD license. The GPL is not just the most popular open source or free software license, it is overwhelmingly the people's choice.
Why the lies about the GPL?
Gates and Ballmer attack the GPL at every opportunity. It's not unusual to hear them break out in that old familiar fascist soft-shoe routine and refer to it or Linux as communistic. Hey, who can blame those two bozos. They stumbled blindly into a pot of gold when they were given a monopoly on what turned out to be -- largely no thanks to them -- the hottest technology of the century. Now their lives are dedicated to protecting that monopoly from all comers.
They've done pretty well at that, too. Sometimes they've won anti-trust battles in court, sometimes they've won them in back room deals with secretive administrations. But several superior technical solutions have come and gone -- DR DOS and OS/2, for example -- without making much of a dent in the Microsoft monopoly.
But Linux is immune to most of the kneecap-busting, air-supply cutting, baby-knifing techniques that Microsoft is so fond of. Linux is not a company or an individual that can be bought. It's a community made up largely of folks who find the Microsoft mindset disgusting. Geeks like things that work, and despise the hollow-men who make hollow claims about performance, security, robustness, and availability. And -- unlike the TCP/IP stack and Kerberos -- it's protected by the GPL.
You know those bogus and misleading ads that Microsoft calls its "Get the facts" campaign, and loves to run here and on other popular Linux sites? That's not only what Microsoft does best, it's about the best it can do in its campaign against Linux. And judging from the feedback reactions I've seen to them in comments, they aren't winning any converts for them.
Stallman as a substitute target
The GPL is a license for software. Words. Statements. Clauses. A legal document. Richard Stallman is a man. Brilliant, opinionated, and uncompromising. Many attacks on the GPL are made indirectly, by going after Richard Stallman, for no other reason than he is vulnerable to them, while the license itself is not.
If you don't disassociate the two, then the GPL is going to rise and fall in your estimation based on how you're well getting along with Stallman at the moment. Remember, we're talking about a man who can polarize a room into warring factions just by walking by. I admire Stallman greatly, but I don't always agree with him. It's perfectly OK to like the GPL and to dislike Stallman. They are two different things.
The bottom line
The reason I love the GPL is because it has made one of the richest men in the world -- some would say that makes him one of the most powerful men in the world -- impotent against the surging growth of Linux and its user base.
And because Linux and other free software exists, I have been able to free myself from the noxious terms and conditions imposed by the monopoly on their customers. Changing their licensing terms on the fly, for example. And doing so in ways which forces meek compliance, since failure to accept them means you don't get the latest service pack, which contains fixes for dozens of gaping security holes, which are known and constantly probed for every minute of every day.
The monopoly hates the escape route the GPL provides me. That's why they constantly attack it. Those attacks will undoubtably continue. Some will be legal challenges, some will merely be insane. Sometimes the hand of Microsoft will be obvious -- as in its financial backing and support of SCO -- sometimes not. But it doesn't matter. The GPL is winning. And for that I love it all the more.