The German Remote Sensing Data Center (DFD) has developed a digital library for the long-term management of earth observation data products. This Product Library is a central part of DFD’s multi-mission ground segment Data and Information Management System (DIMS) currently hosting one million digital products, corresponding to 150 Terabyte of data. Its data model is regularly extended to support products of upcoming earth observation missions. The ever increasing complexity led to the development of operating interfaces which use a-priori and context knowledge, allowing efficient management of the dynamic library content. This paper presents the development and operating of context-sensitive library access tools based on meta modeling and online grammar interpretation.