The free software movement: E-hippies who want to save the world

Let's say you go to a garage sale and buy a chair.

What a nice chair.

It's a nice chair and everything, but after a while you realize you have too many chairs. But you have this massive dog who likes his food bowl up high. So you do the natural thing and turn the chair into a dog bowl holder.

You're welcome, Rover.

But then you're moving to a new city and you really can't be bothered to bring the chair-slash-bowl-holder. So you sell it at your own garage sale. The person who buys it doesn't have a dog but likes to garden. So they tweak your design a bit and now have a nifty flower pot holder.

Bear with me: yes, you're still reading a CS blog.

And everyone's happy, right? You go about your merry way and everyone who sees the chair tells you how clever you are and it feels pretty great.

Now let's say you buy some fancy program. It does almost everything you want it to, but it needs one or two more features to be perfect. No matter; you're a CS superhero and those features really wouldn't be that hard to implement, so you do your hacky magic and have the ideal software. You send it to some friends who all say you're very clever, and you feel all warm and fuzzy inside.

Until the cops show up at your door asking you about copyright infringement.

This is where owning software is different from owning anything else. Even if you buy it and have it and it's "yours," you don't own it. You don't have complete freedom. And that seems a little messed up: we live in a culture where "once you buy something, you own it" is pretty much policy (stereotypical American, right? "YOU CAIN' TELL ME WHAT TO DO WITH MAH PROPERTAY").

That's where the free software movement comes in.

The free software movement, which was officially founded by Richard Stallman in the eighties with the launch of the GNU project) isn't about making sure you never have to pay for software ever again (though I feel like we're definitely tending that way as a society, and as a broke college student I'm totally okay with this). Instead, the movement promotes four "essential" freedoms for users:

(0) freedom to run the program,
(1) freedom to study and change the program in source code form,
(2) freedom to redistribute exact copies, and
(3) freedom to distribute modified versions.

You'll notice that none of that says "users should be free from having to spend money for a collection of ones and zeroes"; when you see "free software," it's free as in speech, not necessarily free as in beer. Sorry.

Stallman himself has terrible-quality webcam videos explaining the philosophy behind free software: (CS celebrity alert!)

At the heart of the free software movement is the idea of copyleft, a "general method for making a program (or other work) free, and requiring all modified and extended versions of the program to be free as well."

To copyleft a program, we first state that it is copyrighted; then we add distribution terms, which are a legal instrument that gives everyone the rights to use, modify, and redistribute the program's code, or any program derived from it, but only if the distribution terms are unchanged. Thus, the code and the freedoms become legally inseparable.
Proprietary software developers use copyright to take away the users' freedom; we use copyright to guarantee their freedom. That's why we reverse the name, changing “copyright” into “copyleft.”
Copyleft is a way of using of the copyright on the program. It doesn't mean abandoning the copyright; in fact, doing so would make copyleft impossible. The “left” in “copyleft” is not a reference to the verb “to leave”—only to the direction which is the inverse of “right”.

You can (and should!!) read about copyleft here and here, and there's also a whole series of pages about the underlying philosophy of the free software movement.

The origins of the free software movement and copyleft are described in the documentary Revolution OS, which is much more than "a documentary about Linux." And it's freely distributed (because, really, it would be weird if it wasn't), so you have no excuse not to watch it if you haven't already. You can torrent it here or watch the whole thing on YouTube here.

Really, this should be required viewing to pass 46A

Free software has done a lot for us. Apache's web services are community-developed and free to use, and they host more than 60% of all web pages whose servers we know. OpenOffice and LibreOffice are free replacements for Microsoft's Office Suite. Adblock Plus makes the Internet a less annoying place. I use Notepad++ and GCC to write and compile my C code. I've used Anki to study. I think you get the idea. The free software movement has contributed to some fantastic code out there, and since projects have an entire community behind them, they continue to evolve and create a more diverse and robust collection of software.

So stop hogging all your code to yourself. You're not helping anyone. You jerk.