We have developed a tool for the authoring of adaptive CAL courses, called “Dynamic Courseware Generator” (DCG). It generates an individual course according to the learner's goals and previous knowledge, and dynamically adapts the course according to the learner's success in acquiring knowledge. The DCG runs on a WWW server. The learner receives from this server an individualised course targeted to a specified goal. Afterwards, s/he is adaptively guided by the course through a space of teaching materials on the WWW. Unlike other CAL courses on the WWW, a course produced by the DCG is interactive, it tests the learner's knowledge and dynamically adapts to the student's progress. The authoring tool can be used also for collaborative authoring and learning.