This paper presents the design, features and pilot evaluation study of a web-based environment--the SORTING environment--for the learning of sorting algorithms by secondary level education students. The design of this environment is based on modeling methodology, taking into account modern constructivist and social theories of learning while at the same time acknowledging the role of hands-on experience, the significance of students' expressing their previous knowledge, the importance of interlinked multiple representation systems (MRS) and the role of constructive feedback on student learning. Although SORTING supports student learning of typical sorting algorithms such as Bubble-sort, Quick-sort and Selection-sort, it can also be adapted to integrate more sorting algorithms. The analysis of the data emerging from the pilot evaluation study of SORTING has shown that students used all the representation systems (RS) provided and found them attractive and easy to use. On the whole, student interactions within SORTING helped them to become aware of both the intuitive and the typical sorting procedures used, to conceptualize them, to overcome learning difficulties, to correct themselves and to make connections between different representations of the sorting algorithms used.