JWS Online is a systems biology tool for the construction, modification and simulation of kinetic models and for the storage of curated models.
Simulink is an add-on package for MATLAB that supports simulation and model-based design using a graphical block-programming scheme. An interactive graphical editor is provided for building models and simulations based on an extensive library of customizable program blocks and custom code. A Model Explorer application supports inspection and editing of models, signals, parameters and generated code.
STELLA (Systems Thinking for Education and Research; from isee Systems) is a modeling software package that diagrams, charts, and uses animation help visual learners discover relationships between variables and helps simplify model building. Stella handles time series, sensitivity, and simulation models well and has a 'drag and drop' modeling interface. Users can download a free trial that has significant features.