can client

MLDonkey is a multi-platform multi-network peer-to-peer client.

A minimal (and elegant) Twitter client

Native OS X desktop client for the Yammer messaging service.

Waveboard is a client software for Google Wave

Desk Client that connects both Twitter and Facebook

Optimized Twitter client for Mac

Twitter client with a real OS X look and feel.

A beautifully designed and very functional Twitter Client

a simple and elegant Twitter client

A Twitter client with message store capability