“OPENMODELICA is an open-source Modelica-based modeling and simulation environment intended for industrial and academic usage. Its long-term development is supported by a non-profit organization – the Open Source Modelica Consortium (OSMC).” OpenModelica aims to provide an enhanced, Open Source Modelica modeling and simulation environment and this thesis is an addition in this direction.  The purpose of this thesis is to create a web based graphical connection editor. There are other open-source connection editors available, but these editors were desktop applications. There is one web based editor but it is a textual editor. Desktop applications need installation and space on the local system. OMWeb connection editor is the first web based graphical connection editor that runs on a web browser. It’s a web platform for OpenModelica and provides the environment for modeling and simulation in the Modelica Modeling Language. The OMWeb connection editor can run on any system without the need for an OpenModelica installation. If a system is connected to the internet, and contains a web browser, it can run the OMWeb connection editor. The OMWeb connection editor uses Java Runtime Environment to run an applet in the browser. The user can create models graphically; but they can also be viewed in the textual format. The user can simulate and plot his models. The plot file generated for the model can be downloaded from the server.  The OMWeb Connection Editor uses Servlet to handle requests from the client. The servlet is responsible for the communication with OpenModelica Compiler. It also gets the results from OMC and sends them back to the client. In our case the browser is the client.