Jarnac is a language for describing and manipulating cellular system models and can be used to describe metabolic, signal transduction and gene networks, or in fact any physical system which can be described in terms of a network and associated flows.

Jarnac is based on a simple control language, similar to the Basic language and supports many of the constructs one would expect, for loops, conditionals, while/do and repeat/until. It supports at least 7 different data types, including integers, floats, Booleans, strings, vectors, matrices and lists. Jarnac also supports user defined functions and external modules.