The objective of this paper is to present a Java-based simulation package (SimDynamic) for modelling, simulating and analysing dynamic systems on the Web. The package is a collection of several functional nodes and these nodes serve as the basic building blocks of a model. A model is constructed by building a directed graph with nodes and edges. A model of moderate complexity can be constructed with minimal of effort and without writing any code. Finally the package allows maximum user control of model execution and provides both graphical and numerical output.