Abstract In the collision of ultrarelativistic lead ions with nuclear targets at the CERN SPS up to several thousand charged particles in the momentum range of 0.1–200 GeV/ c are produced. These events have been recorded by the large-volume tracking detectors (TPCs) of the experiment NA49. In order to analyse the huge amount of data (typically 10 TBytes per run) a software environment was developed at the University of Frankfurt. This system describes the detector information, basic data types and their relationships as C structures. The structure management is based on the dynamical memory management available in C. The implementation as a client-server architecture allows mixed-language programming and sharing of resources like visualization applications. Client and server communicate by standard UNIX network tools, thus providing interoperability between applications on different machines in heterogeneous distributed environments.