Prominent iOS developer Tapbots has just served up the long-awaited and oft-rumored Tweetbot for Mac in free alpha form on its website. The app is pretty much exactly what you'd expect — a beautiful gray-blue Twitter client for power users — yet it's nowhere close to finished. So why release the app to the public so prematurely? Tapbots developer Paul Haddad said, in a blog post:

We've decided to release it as a public alpha to a) motivate us to finish faster, and b) get feedback to help us build the best Mac incarnation of Tweetbot we can make.

Tweetbot for Mac has been under development for the last six months and has proven to be enough of a challenge that Tapbots for the first time added a new member to its team. Developer Todd Thomas was enlisted to "bring Tweetbot to the Mac," according to the blog post, while most of the underlying code is Haddad's.

The level of detail you'd expect from Tapbots is here, from the button glyphs to the app icon — which at this point, is a gray egg with a Tapbots logo on it. You can even double click the Direct Messages icon to mark all messages as read, which is one of our favorite features from Tweetbot for iPhone and iPad. Tweetbot for Mac looks great, but suffers from the usual gambit of bugs and inconsistencies you'd find in any pre-beta app. "Don't say we didn't warn you," Haddad said. "Sending bug and crash reports will help us out a lot." There's a simple "Send Feedback" button in Tweetbot for Mac's help menu.

Unfortunately, the app couldn't come at a worse time. While Twitter hasn't paid much attention to its Mac app lately, we'd assume that if it does decide to crack down on mobile apps using its API, it'll also crack down on Mac apps (like Osfoora, and now Tweetbot). As a final judgment from Twitter looms, Haddad and company are hard at work porting many of the Tweetbot features that make it arguably the best Twitter client out there — features like "mute" and iCloud syncing absent from Twitter's official apps.

Tweetbot for Mac is Retina-optimized and works today on Macs running OS X Lion, but will only work on Macs running OS X Mountain Lion at launch. iCloud and Notification Center support will be missing until the app launches, since Tapbots is unable to implement these features until the app is signed by Apple. The app will remain in alpha/beta "as long as it needs to be," Haddad said. "We won't sell anything short of a quality product."

Grab the Tweetbot for Mac alpha here.