The Usability Engineering Repository (UsER) and its mobile frontend MUsER compose a flexible, web-based platform to support collaboration in User-Centered System Design. Modules for different stages of cognitive and usability engineering are provided and can be applied as needed. Analysis and design entities can be linked through hypermedia relationships. In this manner, a semantic network emerges from analyzing the context of use through design up to the summative evaluation of the product. Results can be presented in a document with a linear structure and is suitable for purposes like formal project deliverables or contracts. Heterogeneous and distributed design teams can benefit from immediate data exchange, better awareness of co-workers’ activities and appropriate visualizations for different organizational roles and expertise. Images of cognitive artifacts and other findings from user research and field studies in mobile contexts can be documented and shared among project members.