Universal Simulator


"A probable scenario for ecological modelling is that standardized objects for at least some components of ecosystems will be developed and widely distributed in a form that can be used in many different models." - Silvert W (1993), Ecological Modelling 68: 91-118.

"What modellers need is a standardized set of tools that will enable them to collaborate and share model components, pieces of well-defined software objects that can be interchanged and combined freely: Download the annual life cycle models of species A and B, combine them with soil model C and weather generator D, and set it all in the context of cropping system model E. We need a way out of modeling as a purely personal, or in the best case, small-team exercise." - Holst N (2010), Weed Science 58: 497-502.


"Proprietary code has no place, neither in science where the code itself, the ecological model, is the very substance of the science, nor in politics where models form the evidence upon which policy decisions are taken." - Holst N (2013), Ecological Informatics 13: 70-76.

Universal Simulator

Universal Simulator is a software package for collaborative ecological modelling. It is composed of a GUI main module which is used to open and execute model specifications read from XML files. The XML files specify the components constituting a model. The functionality of these components are defined in plug-in libraries. This makes UniSim extendible and open for re-use. It is programmed in standard C++ but relies on the Qt library. Universal Simulater is open source (GPL).

Update (16 March 2016)

Universal Simulator is currently being extended with a better syntax than XML for model specification. Moreover, this coming version will integrate smoothly with both R and MatLab and will run on Linux and Mac OS, in addition to Windows.

I thank the first four batches of students for their perseverance during the autumn online courses. Without their participation I would never have realised the imperfections of Universal Simulator, thus showing me the way for improvement.


The development of Universal Simulator has been supported by PURE, ENDURE, ICROFS and BiosafeTrain. Flying squirrel icon provided by Yoji Inata (icon N86) and redrawn by David Driessen.