Sometimes you need create a scripting language to control a complex application.
Creating a language from scratch is hard because you need to develop an engine that is able to parse and process the language commands.
XML is a format that is easy to parse, and so it can be used as an alternative to create new file formats or languages that are easy to parse.
This class implements a scripting engine using XML based source code. The scripting engine can be extended with new commands that are processed by new custom PHP classes.