Modern on-line collaborative learning environments are to enable and scale the involvement of an increasing large number of single/group participants who can geographically be distributed, and who need to transparently share a huge variety of both software and hardware distributed learning resources. As a result, collaborative learning applications are to overcome important non-functional requirements arisen in distributed environments, such as scalability, flexibility, availability, interoperability, and integration of different, heterogeneous, and legacy collaborative learning systems. In this paper, we present a generic platform, called Collaborative Learning Purpose Library, which is based on flexible fine-grained Web-services for the systematical construction of collaborative learning applications that need to meet demanding non-functional requirements. The ultimate aim of this platform is to enhance and improve the on-line collaborative learning experience and outcome in highly distributed environments.