[If you had to put the GPL into really simple terms, how would you go about describing it?] Probably the easiest way to summarize the GPL is that it's like a Bill of Rights for software. So just like in the United States we have certain fundamental and inalienable rights, GPL gives you those inalienable rights for the programs you use, and everything on your computer. And especially as we become more and more reliant on technology, and technology sort of dominates everything we do, I think having a base that we have true ownership of and that we have fundamental freedoms around becomes more and more important. [Could you tell us a bit about why WordPress is specifically GPL-licensed, as opposed to BSD or any other license?] Sure. So GPL for WordPress was a decision made before I even understood what it meant, because b2— which WordPress was built on—was also GPL. Later, when I began to appreciate the nuances of the different open source licenses, GPL has still been my favorite, because I feel it's the most moral of all the licenses. The GPL has a clause which basically says that if you build something on top of a GPL product, it must also be GPL. So the freedoms are maintained, even in derivatives, or things that are built on top of it. That's why all plugins and themes for WordPress are also GPL. This engenders an incredible amount of creativity because it allows things to build on what came before, versus other licenses, where a lot of innovation and development might happen on something that's essentially closed-source. It's based on open source code, but there's no reason for anyone to release it, so essentially all that development goes into a sort of innovation black hole. [So what's the difference between me charging for a GPL theme or a premium, non-GPL theme? Why is one OK and the other one not?] OK. So there's nothing in the GPL that says you can't charge for it. That's one of the freedoms, in fact: the freedom to use the software for any purpose. You can sell it; you can do whatever you like. But if you do sell a copy to someone, or if you do redistribute your derivative product in any way, you can't take away freedoms from what you're distributing. So for example, if I made a theme and I sold it to you, that's fine, but I can't say you can only use this on one site. Or you have to leave my link in the footer, or something like that. You should have the ability to modify it, just like you can modify WordPress. [So if I see something labeled a "premium theme", how do I know which ones are OK and which ones aren't?] I think licensing is a complex issue. It's totally fine if someone new to the WordPress world doesn't realize the ramifications of the GPL. I think that the reason that it's important that we stick to it— stick to our principles around it—is that WordPress itself wouldn't exist if it weren't for the freedoms afforded by licenses like the GPL. The fact is that when WordPress started, it was a piece of software that was abandoned, and we were able to take it as a community and build on it. And also, the wide variety of plugins and themes available for WordPress already, if WordPress would have had a proprietary license, or b2, its predecessor, had a proprietary license, none of that would have been possible, and none of us would be here in the first place. So it's kind of like all the things that got us to this point we shouldn't turn our back on those just because it's possible to make some money or it's popular to make some money in a certain way. Just because you can make money doing something doesn't mean you should do it. You can make money selling drugs. You can make money doing anything. It doesn't make it right. Or just because you can get away with it doesn't mean that it's the right thing to do. [So why does the GPL apply to themes and plugins, when they're not actually WordPress, they're things someone else has made from scratch?] So the key—the reason why plugins are GPL— is because they hook into the core WordPress hooks and filters and functions. They use the database class, they use everything like that. So by sort of linking core WordPress GPL code, they inherit some of what's called the virality of the GNU Public License. And the idea from that is it's a license which was created so that everything built on top of the product will protect the freedoms just like the product itself has. The same thing with themes. The CSS and images and JavaScript might be separate, but the actual PHP code that makes up and actually generates the theme uses WordPress functions, it uses the WordPress Loop, it uses WordPress template functions, everything like that. So it, just like a plugin, needs to be GPL. Theme PHP needs to be GPL as well. A good rule of thumb is if you take WordPress out, does the other thing still work? And with most themes and plugins, the answer is no. So they should fall under the GPL. [So how come I can make a custom site for a client, and charge them for it, and not have that GPL?] So a common misconception about the GPL is that let's say I'm hired to make a theme for a client; does that theme fall under the GPL? The answer is no, because it's not being distributed. When something's distributed, it's available for download to the public, you're selling it in a store, or it's a mass distribution. When you do something for one site, or just for yourself, like for example the theme on my blog, which is just on my blog, it's not being distributed in any way, so the GPL doesn't kick in, until it's distributed. So there's some confusion around things that are premium but kosher by the GPL and things that aren't. So one of the things that we're doing now is making a page on the WordPress Theme Directory that will point to folks that sell themes that are super-high-quality and also have commercial support—things you can buy around them. But all the code is GPL, so you retain all the freedoms that you do from WordPress. And they don't violate WordPress's license or anything. We're going to have sort of a mini-directory of those that point to the different sites. [If I GPL my premium theme, will people just pass it to their friends and not pay me for it?] Some folks are definitely scared of the idea that one person would download their theme and then distribute it to everyone, and then they would only sell one. In reality, this is already happening through piracy. Every single premium theme out there is available for free for download on the web somewhere, if you just look for a little bit. So just like this hasn't affected their business, I think they need to move the value up the chain. So rather than selling just the code, sell the things that are most valuable to folks. When I talk to people who buy premium themes, or who pay for these things, often what they tell me is that it's not that the design or anything isn't something they can get from a free theme, but they really like the community, the support: everything around it. The fact that it has a nice packaged site that spells out the benefits. They know if something goes wrong, there's a forum or someplace for them to go where they can get help. And that's worth money. And so I think we should try to emphasize those, and encourage people to adopt business models which function on economics of abundance, not economics of scarcity. So what we'd like to do is there's a number of people innovating on top of the GPL. They create some cool business models around it. One of these is having themes which are 100% GPL: there are no restrictions on your freedoms, you can redistribute them, you can use them, you can modify them however you like. But they have commercial support available. So let's say you want to use a theme, but you are hoping that if you have a problem with it, there's someone you can— the online equivalent of pick up the phone and talk to. Many of these premium themes have support forums, paid customization help, things like that. And some really nice web sites around them. Some folks were doing this under the GPL, and some folks were doing this with proprietary licenses, that restrict your freedoms and are generally evil. So we're trying to point to the people who are doing this in a way that doesn't restrict your freedoms, to encourage them, reward them, and to help more folks adopt this model. Basically, we're going to have a directory of the Brian Gardners of the world, the StudioPresses and Press75's, and all those, who are doing GPL-based development, and then if you come across one, say a Thesis, which is not, you know to avoid it.