WEAR is a Web-based authoring tool for the construction of Intelligent Tutoring Systems (ITSs) in Algebra-related domains, such as physics, economics, chemistry, etc. In WEAR's authoring environment instructors are able to construct problems and tests and also build adaptive electronic textbooks. In return, WEAR generates an intelligent learning environment in which students can solve problems and study the topics of the curriculum. WEAR apart from modelling the student which is a common practice in almost all ITSs and ITS authoring tools, deals also with modelling the other class of its users: the instructors. Based on the user models it maintains, WEAR adapts the interaction with both students and instructors and provides them with individualised feedback and help.