To analyze complex data we need to visualize it and to interact with it. Mondrian is a novel information visualization engine that lets the visualization and the interaction be specified via a script. Rather than featuring a dedicated scripting language, we designed Mondrian to use the hosting language for scripting. Our original implementation is in Smalltalk, and makes use of the dynamic nature of the language to provide an expressive scripting language. Several other implementations of the concept have been built in other languages as well. Mondrian is based on a graph model and works directly with the objects to be represented.