The Modelica language (www.modelica.org) has become a de facto standard for systems modeling and many tools exist. This paper describes certain modern enhancements and a static web app implementation called Modiator (Modelica Instant Simulator). It allows an improved immediate first-time user experience since the web app is available in seconds and simulations can be done directly in the browser. State of the art numerical solvers from the Sundials suite have been compiled into WebAssembly. The Modelica model is translated into Javascript code using techniques such as sorting, tearing, index reduction, state selection, etc. A subset of Modelica is supported with some extensions, for example, support for self-modifying models. This paper also presents the Fluid1D and Model3D libraries.