Yahoo! has released Yahoo! Messenger 8.1 which is compatible with Windows Vista.

Ad Destroy is a free addon for Yahoo! instant messenger that enhances the core functionality of the instant messaging client and allows you to:

1) Disable advertisements from chat windows
2) Enable Polygamy: Sign into multiple email accounts at the same time
3) Tabbed chat windows
4) Toggle Yahoo! nicknames on or off
5) Enable or disable chat wordfilter