During the development cycle of the clickstream software, version 4.0 of the ArsDigita Community System (ACS) was released. Since the original software was built on top of the ACS, the clickstream software was upgraded to take advantage of 4.0 features. There are two benefits to a 4.0-compliant clickstream system. First, the clickstream system is available in one self-contained package. This self-contained package includes the clickstream data models, the population code, the client-side logging system, the server-side reports system, and all of the configuration parameters inside an XML file. A second benefit to the ACS 4.0 system is subsite support. Under the ACS 4.0 architecture, multiple instances of a package can be instantiated. This feature greatly simplifies the goal of supporting multiple clickstream sites on the same clickstream server.