Native alternatives for non-windows platforms - Pidgin (works with Yahoo!, MSN, ICQ and many others, but without Audio or Webcam support.)
Old Versions of the Software can be downloaded in OldApps
This is an application also good for the Dogfood Challenge (later, when it works...).
When reporting test results, please follow exactly the definitions for the test results! To make it clear: if it didn't run or is unable to connect to somewhere, this is a major lake of function. So it is garbage.