Canary. Open, free, and with no ads.

• Canary is a Twitter client that is beautifully designed, fun to use and has everything you'll ever need.

  Canary's user interface is slick and straightforward and helps you do what matters most fast and easily. It does more than you would expect it to and the best part: it's free with no ads.

  

• Beautiful user interface

  Slick and easy to use with minimal footprint; less than most AIR or native clients.
  Minimal error messages and hassles; Canary handles most issues on the background and connects asynchronously to Twitter so that it doesn't block indeterminably

  Multiple timelines

  Read your friends tweets, the public your replies, favorites, own tweets and your direct messages separately.

  See everything

  Canary recognizes (and underlines) URLs, hashtags, ISBNs, ISSNs.
  Switch between screen names and usernames
  Fully supports Growl notifications.
  Indicates protected statuses.

  Actions

  Add or remove, block or unblock users on the fly.
  Favorite and retweet any tweet.
  Visit users' home or twitter pages.

  Filters

  Fully powered: use the rule editor to filter your timelines with precision or instantly with InstaFilters.

  Multiple personnae

  Login in and out of multiple Twitter accounts in an instant.

  The power to shorten

  Choose between Adjix, Bit.ly, Cli.gs, is.gd, Snipurl, TinyURL, tr.im and urlBorg to shorten your URLs. Canary saves and reuses your authentication credentials automatically.
  Automatic URL shortening on paste.

  TwitPic-enabled

  Drag and drop any picture to TwitPic or take your own picture.

  iTunes integration

  Update your followers with the track currently playing on iTunes.

  Secure

  Signed application executable so you know nobody's messed with it.
  Stores your Twitter credentials in the Keychain securely.

  Additionally...

  Researcher friendly: Recognizes DOI and HDL identifiers and resolves them to the original articles.
  Recognizes and resolves IETF RFC numbers and NBN identifiers.
  Optional automatic updates with Sparkle.
  Retrieves the maximum number of updates allowed since last use.

Canary source code is written in Objective-C (Cocoa) and is currently released under an MIT-style license at GitHub.

You can download this project in either zip or tar formats.

You can also clone the project with Git by running:

$ git clone git://github.com/macsphere/canary

Canary is currently released as a public beta so certain things are bound not to work properly. You can get the beta version of Canary here.