Certain special purpose graphical displays have been integrated into the software. These reflect the needs of molecular biologists in constructing genetic and physical maps of genomes. It is written in the C programming language and uses the X11 windowing system to provide a platform independent graphical user interface. The source code is publicly available. This is nevertheless a general database management system using caches, session control, and a powerful query language.
Typical objects are clones, genes, alleles, papers, sequences, etc.
Maps are derived from data stored in tree objects, but precomputed and stored as tables for efficiency. The system of models allows flexibility and efficiency of storage -missing data are not stored. A major advantage is that the models can be extended and refined without invalidating an existing database. Comments can be added to any node of an object.