The paper deals with experience management in computer-mediated environments. It particularly focuses on complex tasks whose support relies more on experience than on knowledge. The presented approach is based on the ?use traces? concept to investigate the ?activity reflexivity? as a first step in experience management, and experience sharing and reusing as possible applications. The paper also outlines the framework supporting Trace-Based Systems creation. Traces, trace models and trace life cycle are formally defined. The main parts of the framework architecture: collecting, transformation, visualization, and query systems are also detailed.