It is possible to perform good system dynamics work with other tools including programming languages. However, this is not usually very practical. Just to ensure complete disclosure, Bob Eberlein, who maintains these pages, is also the developer of Vensim. The software titles are listed in alphabetical order. A brief, largely historical, introduction is given for each.
Corrections are welcome.
Additional information can be obtained directly from the vendors. Originally developed by Jack Pugh at MIT the language was made commercially available from Pugh-Roberts in the early 1960s. It provides an equation based development environment for system dynamics models. The stock and flow diagrams, used in the system dynamics literature are directly supported with a series of tools supporting model development. Equation writing is done through dialog boxes accessible from the stock and flow diagrams.