We describe a learning environment (MEMOLAB) that illustrates the distribution of roles among several agents. The learner solves problems in interaction with an expert, i.e. an agent who is able to solve the same problems through the same interface. The degree of assistance provided by the expert is tuned by another agent, the tutor, which monitors the interaction. MEMOLAB includes several tutors corresponding to various teaching styles. These tutors are selected by their superior, called ‘the coach’. This distribution of roles between the agents has been conceived in such a way that some agents (the tutors and the coach) are not directly concerned by the specific teaching domain and hence can be reused to build other learning environments. The set of domain-independent components constitute ETOILE, an Experimental TOolbox for Interactive Learning Environments. Its originality is that authors do not build a software application by writing questions and feedback, but by designing domain-specific agents that will interact with the agents provided by the toolbox.