You can use Thunderbird AutoConfig (MCD) in scenarios of many users sharing computers. Hence a single computer might connect different users throughout the day, who have their personal OS account, maybe including an LDAP account for authentication. The objective is to provide users with Thunderbird as a combined email, communication and PIM client which is automatically configured via preferences at startup for the currently logged-in user on the computer. As Thunderbird can run on various operating systems, this will also work perfectly in mixed OS environments, e.g. with Windows and Linux systems. Instead of configuring individual preferences files for each end user (prefs.js), you can now use a centralized default set of preferences. This default configuration file can control preferences using a set of API functions and based on environment variables (USER, HOME...) and/or LDAP queries from an organisation's directory.