While stalking people recently, I had a little conversation with Jamison Kelly, who asked,
@michaeltwofish Tell me: what would make a Wordpress geek go to Habari?
It may be a tall order to convince someone who calls themself a 'WordPress geek' that anything else is going to meet their needs, but I'm assuming a willingness to listen. I mentioned a couple of reasons in reply, but I think the question deserves a reply of more than 140 characters.
I think there are great reasons that a WordPress geek might want to move to Habari, and benefit from doing so. These are a few reasons why I think Habari is a good place to be. In the spirit of full disclosure, I should say that I've done much more development on Habari than WordPress.
Community
The first thing that attracted me to Habari was the community, and I've written before about how much I love it. It might not have the size of the WordPress community, but try mentioning some problem you're having with Habari on Twitter, or identi.ca, or FriendFeed. Or drop in to the #habari IRC channel on Freenode (try the LiveHelp plugin if you're not familiar with IRC). The promptness and friendliness of the support is generally fantastic. And I'm not just talking about some peripheral community that's built up around the software, I'm talking about the core developers as well.
Meritocracy
I think one of the reasons the community is so responsive and helpful is that people are rewarded for their participation. This is the idea of a meritocracy, the organisational model that Habari is based on. The people who show the ability, dedication, and willingness to contribute, get given the power to do so. It doesn't matter if that contribution is writing code, or documenting Habari, or marshalling the community, or anything else that benefits the project. The main concrete way that contributions are recognised is through an invitation to the Habari Project Management Committee, jokingly referred to as the Cabal, the main benefits of which are voting rights on the project and commit access to the code base. As of the time of writing, there are 25 people in the Cabal. For a project that had its first developer release less than two years ago, that's convincing evidence of the openness of the project. How many WordPress committers are there ? And where do they work ?
It's a small pond ...
... for now. Being such a young project, the pool of developers and themers is quite small. As such, writing a couple of killer plugins or some quality themes can get you a lot of recognition. By starting developing for Habari early, you can really make a name for yourself as it grows.
In addition, Owen has also written about why theme and plugin authors should choose Habari on licensing grounds.
All of those reasons are soft and fluffy, but there are good technical reasons to use Habari.
An extensible platform
It's incredibly easy to write themes and plugins for Habari. Andrew Rickmann has written a good side-by-side comparison of theming for WordPress and Habari. There are hooks throughout Habari that allow plugins to act or filter based on events. This is much the same as WordPress, though Habari doesn't require that you register your functions. So my actionadminfooter() is the same as my actionadminfooter().
Themes and plugins both extend the Pluggable class, by way of the Theme and Plugin classes respectively. Want to change the way actdisplayhome() works ? Just define the function in the Theme class in your theme.php file and Habari will use your code instead of core. In addition, the active theme acts just like a plugin, so you write code to can hook events, just like a plugin can.
And if existing hooks don't let you do what you need, you can override system classes. Want to tweak the way Utils::slugify() works ? No need to tweak the core, just copy system/classes/utils.php to /user/classes and change it to work how you'd like.
The ease with which Habari can be extended, customised, and bent to your own evil ends has led one developer recently to implement an issue tracking system on top of it. In three hours.
got irritated by the lack of good, simple issue tracking software written in PHP today. Wrote one on top of Habari in 3 hours. WIN.
Of course, it may be the "WordPress geek" label indicates an emotional position, and not a logical one, in which case I'm really wasting my time. But if you're willing to be swayed, those are some of my - completely subjective - reasons.
Habari users, what are yours ?