We developed a diagrammatic inference system for the World Wide Web. Our system enables the creation of diagrams such that the information contained in them can be searched and inference can be performed on it. We developed an XMLSchema for bar, line, and pie charts. Based on it, we developed software that transforms a corresponding XML file into an SVG image, which in turn is rendered by the client as an image. Additionally, we developed a search engine which enables a user to find information explicitly contained in the XML file, and as such in the image. Furthermore, we developed an inference engine which enables a user to locate information that is implicitly contained in the image. Categories and Subject Descriptors H.3.1 [Content Analysis and Indexing]: Indexing Methods General Terms Human Factors, Standardization. Keywords Search, Inference, Searchable diagrams, Inference system, XML.