In the field of guided learning on the Internet we present, in this paper, an interactive tool for designing intelligent tutoring systems on the web. Our tool makes easier the creation of an ontology describing the content model for a given course. Such ontology contains information about classes and instances, reflecting the structure and components for the later creation of an adaptive course, using our web-based runtime course manager system. Our authoring tool generates XML code to improve course understanding as well as transportability and processing by our runtime system, which means that the generated code will reflect, in an easier way, the course structure and contents, being readable for most of users and course designers.