The document discusses using the open source tools Nagios and Cacti to monitor business metrics. Nagios can be used to monitor things like orders, imported data, and customer activity by creating PHP scripts that return status codes. Cacti is a graphing tool that can visualize business metrics over time through configuration of data input methods, templates, graphs, and tree organization. Both tools involve writing PHP scripts to extract and return meaningful data that the tools can then monitor and graph.