STAR is a tool for the stochastic hybrid analysis of Markov population models, that is, Markov processes with an underlying population structure. It efficiently computes an accurate approximation of the probability distribution at a particular time instant based on a stochastic hybrid model that combines moment-based and state-based representations of probability distributions. STAR is primarily used to analyze networks of chemical reactions as they are of interest in the systems biology domain but STAR is not restricted to those. In fact, STAR can analyze any discrete-state Markov process whose transitions can be partitioned into a finite number of classes (e.g. “birth” and “death” of objects of a certain type). STAR models can be specified using a simple language.

In 2016, the tool was renamed into STAR (STochastic Analysis of biochemical Reaction networks) since biological applications became its main focus. Prior to this the tool was named SHAVE.

Source code download: STAR/SHAVE

STAR/STAR has a free web-based interface that allows users to analyze their models without complicated software installations and without high CPU and memory load on their own personal computers (currently offline).