The AccountManager offers features for managing user accounts and more:

    * enable authentication through a number of built-in authentication
      resources and some more by 3rd party extensions
    * allow users to register new accounts
    * login via an HTML form instead of using HTTP authentication
    * allow existing users to change their passwords or delete their accounts

These features are new in the plugin for Trac 0.10.

    * send a new password to users who've forgotten their password
    * administration of user accounts

These features are new in the plugin for Trac 0.11 and later 
    * login failure tracking and rule based account locking (temporary or
       permanent lock) 
    * per-account details admin page 
    * password hash refresh and store migration on user login 
    * i18n support (requires Trac 0.12 or later) 
    * account meta-data listing from Trac db table session_attribute, with
      cleanup option 
    * Single-Sign-On functionality for applications with multiple Trac
      environments per domain/host 
    * mostly account-/user-related WikiMacros
