Lopez, C.F. et al. Mol. Sys. Biol. 9, 646 (2013).

An increasing number of research studies are combining experimental measurements of a particular process or phenomenon with mathematical models of it, frequently toggling between the two to yield a detailed quantitative understanding. Such models are typically written as equations, which can be difficult and tedious to modify without error or to share. Lopez et al. now describe an open-source framework, PySB, in which the biological models are Python programs. PySB is interoperable with the rule-based languages BioNetGen and Kappa. The resulting models will benefit from popular Python tools for documentation, analysis, visualization and sharing.