MathModelica is a Mathematica extension, which provides a modeling and simulation environment for Mathematica based on the new standard of physical modeling languages called "Modelica". Modelica is a new object-oriented multi-domain
modeling language based on algebraic and differential equations. In this paper we present a language and an environment, MathModelica,
that integrates different phases of the Modelica development life-cycle. This is achieved by using the Mathematica environment and its structured documents, that is, notebooks. Simulation models are represented in the form of structured
documents, which integrate source code, documentation and code transformation specifications, as well as providing control
over simulation and result visualization. Import and export of Modelica code between internal structured and external textual
representation is supported. Mathematica is an interpreted language, which is suitable as a scripting language for controlling simulation and visualization. Mathematica also supports symbolic transformations on equations and algebraic expressions which is useful in building mathematical models.