The plugins have been replaced with scripts, you can find several already on
http://www.msgpluslive.net/scripts/browse/
quote:
Originally posted by changelog on [url
http://www.msgpluslive.net/download/changelog][/url]
Plugins/Scripts:- The old plugins interface from Plus! 3 has been replaced with a brand new scripting interface. The scripting engine makes it easier for everybody to write their own add-ons (providing you know JScript, documentation is provided).
- The new scripting interface is provided with a comprehensive documentation, samples (scripts created by beta testers which are already available in the online script's database) and gives you more than 150 functions/properties/events to interact with Windows Live Messenger, all without having to compile your project from anywhere but Messenger Plus! itself. If you're a developer interested in creating your own Messenger add-in, now is your chance to show off your skills!
- Old plugins can't be loaded anymore but previous plugin developers are encouraged to use the many new features of the scripting interface to improve their previous add-on.
/ 
