JSBML is a comprehensive implementation of datastructures and parsers for the SBML standard in Java ™. JSBMLhas been designed as an application programing interface (API) library that can be used as a back-end in SBML supporting software. It strives to attain a high compatibility to the library C/C++ library libSBML, which also provides a Java API through automatically generated native language wrappers. In contrast, JSBML It is completely platform independent and has been designed from scratch, specifically for the Java™ programming language. Advanced features of JSBML comprise specific change listeners that facilitate keeping track of modifications to the data structure, and modules for end-user applications (for instance, a CellDesigner plug-in module, a compatibility module for libSBML etc.). JSBML implements all currently defined extension packages for SBML, including "qual". Its sophisticated type hierarchy and flexible data structure can be used as internal data representation of end-user software.