History

How the add-ons and plugins of the 2000s worked, and what happened to the software they extended.

• 
  The messenger add-on era: multi-login loaders, patches and the end of Yahoo! Messenger

  A short history of the third-party add-ons built for Yahoo! Messenger, AIM and MSN Messenger in the 2000s, why they existed, and what happened to the networks they extended.