One of the most appreciated features of RRDTool is the built-in graphing function. This comes in useful when combining this with some commonly used webserver. Such, it is possible to access the graphs from merely any browser on any plattform.
Graphing can be done in very different ways. It is possible, to graph one or many items in one graph. Autoscaling is supported and logarithmic y-axis as well. You may stack items onto another and print pretty legends denoting characteristics such as minimum, average, maximum and lots more.