You are right as well that if someone has paid for something they are unlikely to want to then go and give that away for free.

I think trust should work well for you and the community as a whole. At least I hope it does.

Of course, since it is GPL, they can pretty much do whatever they want with it, even distribute it to non-club members.

This extension isn't something they're entitled to as a club member, but I thought I'd give it a try to see where it leads. I might even do something like give club members access to things months in advance before publicly releasing them.

No matter how it works out, I'm trying to avoid the whole issue altogether by just releasing everything under the GPL and charging for support services, which has been working out fairly well at this point in terms of business.

My interpretation of the GPL and themes is that CSS and images can be licensed separately. However, I'd rather look at business models that don't potentially put my business at risk, which is why every new theme I release will be licensed with the GPL.

Of course it is worth stating that the only reason this is an issue is because there is a repository that requires themes to be GPL to be in it. Beyond this licensing is only really an issue when you need to enforce it.

And yes, I did expect you to say that :-)

WordPress theme construction is such that you have a specific file for a specific type of request. For example, you may have a template file that represents the response to give when requesting a single post: single.php. In Habari, this file is named something else, but it exists (if you don't look any deeper).

To give a counter-example, in Drupal you produce a single page.tpl.php wrapper template, which would be like a WordPress template with the header and footer includes built in, but in place of the content area you simply (to simplify) output the “$content” variable. When you make requests for specific types of things, Drupal fills in that content variable with the type of thing your requested based on templates specific to the things you request. So if you request a post (which in Drupal is a “node” of type “blog”) it gets the node.tpl.php template file (or the node-blog.tpl.php file if that exists), uses it to build that node's output, then inserts it in the page.tpl.php's content spot. It does this if there is one post or many posts, using the same two templates, just repeating the one in a loop if there are multiple posts to display.

As you can see, Drupal's is radically different from WordPress' template model. Interestingly, with not too much additional work – and soon to be much less, I think – Habari can work this way too. (But you were expecting me to say that, weren't you?)

My question: Is there another blog package that is sufficiently the same in its theme structure but not also GPL-licensed that you could reasonably say that your output is platform-neutral, not WordPress-specific, thus able to use a non-GPL license?

I'm not sure of the answer, but it's an interesting intellectual puzzle.

Obviously, I'm on the side of creating and distributing themes for Habari under the ASL. Since the ASL is GPL-compatible, that means that someone (or you) can take the code you produce for Habari and make a WordPress or Drupal theme out of it. And since Habari itself is ASL, you can create a theme under any license you want, and do whatever you want with it, including charging for commercial/premium themes and restricting their redistribution or freely releasing your own theme under an appropriate OSI-approved license. It's a win for themers, it's a win for users, it's a win for free software.