phpCallGraph is a tool to generate static call graphs for PHP source code. Such a graph visualizes the call dependencies among methods or functions of an application. Arrows represent calls from one method to another method. Classes are drawn as rectangles containing the respective methods. The graphs can be leveraged to gain a better understanding of large PHP applications or even to debunk design flaws in them.
It is also possible to visualize calls to internal functions of PHP and to some extend call dependencies among different classes. Have a look at the example call graphs to get an impression.
Great tool, thanks Falko!