was the first final specification, and is used to describe many of the models in the CellML Model Repository. CellML 1.0 has some biochemistry specific elements for describing the role of variables in a reaction model. CellML 1.1 CellML 1.1 introduced the ability to import components and units. In order to fully support this feature, variables in CellML 1.1 accept variable names as initial values. Metadata specifications CellML has several metadata specifications, used to annotate models or provide information for running and/or visualizing simulations of models. The metadata 1.0 specification is used to annotate models with a variety of information; relevant references, authorship information, the species the model is relevant to, and so on. Simulation metadata provides the information required to reproduce specific simulations using a CellML model. Graphing metadata provides information to specify particular visualizations of simulation output, for example to reproduce a particular graph from a paper. CellML.org CellML.org aims to provide a focal point for the CellML community. Members can submit, review, and update models and receive feedback and help from the community. A CellML discussion mailing list can be found at CellML-discussion mailing list. The scope of this mailing list includes everything related to the development and use of CellML. A repository of several hundred biological models encoded into CellML can be found on the CellML community website at CellML Model Repository. These models are actively undergoing a curation process aiming to provide annotations with biological ontologies such as Gene Ontology and to validate the models against standards of unit balance and biophysical constrains such as conservation of mass, charge, energy etc. References External links CellML homepage IUPS Physiome Project Physiome JAPAN Project Interactive cell models Java versions of many of CellmL cardiac models. See also SBML BioPAX XML markup languages Mathematical markup languages XML-based standards