Cricket is a high performance, extremely flexible system for monitoring trends in time-series data. Cricket was expressly developed to help network managers visualize and understand the traffic on their networks, but it can be used all kinds of other jobs, as well. Cricket has two components, a collector and a grapher. The collector runs from cron every 5 minutes (or at a different rate, if you want), and stores data into a datastructure managed by RRD Tool. Later, when you want to check on the data you have collected, you can use a web-based interface to view graphs of the data. Cricket reads a set of config files called a config tree. The config tree expresses everything Cricket needs to know about the types of data to be collected, how to get it, and from which targets it should collect data. The config tree is designed to minimize redundant information, making it compact and easy to manage, and preventing silly mistakes from occurring due to copy-and-paste errors. Cricket is written entirely in Perl and is distributed under the GNU General Public License.