I’m with Erik, who simply asks:

Huh? Why?

I like choices; alternatives; competing options. And as such, a contender in this space seems warranted, what with Proteus having died a silent death (I can’t even find a website any more), and Fire recommending and helping its users migrate to Adium. Aside from the ‘official’ choices such as iChat, Yahoo! Messenger (which seems to have gone into a-beta-a-year mode, sadly enough; it looked promising) and MS Messenger for Mac (whose interface still looks fat), that leaves only Adium.

But Adium isn’t popular as a least-evil choice, or due to tactics hostile to its competitors. It’s popular because it happens to be a very well-designed application, done by talented developers. Its interface is simultaneously ultra-simple and yet highly customizable, and its underlying workings leave little to be desired. Not nothing (despite the obvious difficulties, audio and video support would be nice to have; also, file transfers still range from slow for MSN to fast but intermittent for AIM to never-working for ICQ), but decidedly little. That makes it hard to compete with, for good reason. In fact, when it comes to the user interface, I keep looking at various IM applications on Windows every now and then (particularly Pidgin, but also Miranda and Trillian), and remain convinced that Adium is not just the best choice on the Mac platform, but also far beyond anything available on Windows. I sorely miss it there. (Fortunately enough, Pidgin has finally started catching up.) Backend-wise, I understand Miranda’s ICQ support is better, but that’s only relevant for less than a handful of people I talk to.

Trillian, though? Trillian’s interface screams “flashy”, not “thoughtful”. It’ll have an extremely hard time competing. And when it comes to this screenshot they’re showing off, that looks like a future version of MS Messenger for Mac. It comes nowhere near Adium’s elegance.

And so, I second this apt query in a comment:

Adium is pretty much the de-facto IM client for OS X. Regardless of how it’s described, Astra’s release is a direct competition call against Adium. Hence the question – how is it better than Adium? Why would people switch?

Cerulean Studios should think long and hard on whether they can provide good responses to these two questions.