In addition to the Microsoft Installer (MSI) packaging format, Microsoft provides a quicker and easier way for you to leverage Active Directory (AD) and Group Policy for making your existing applications available to your Windows 2000 (Win2K) users. Group Policy-based software installation's publishing feature supports a new format called Zero Administration Packaging. ZAP files are simply text files that let you call an existing application's setup program without having to repackage that setup. You can also tell your ZAP files which file extensions the application supports, so that if a user opens a file with the associated extension, the system triggers the application setup routine. Using the ZAP format doesn't provide you with any of the self-healing, component-based benefits available to MSI packages, but it does let you quickly publish applications to the directory for your users.