title: how to develop an add-in for visio
body: <p>I want to create an add-in to visio so that I can draw BPMN diagrams (Business Process Modeling Notation). A similar work is available here: <a href="http://www.interfacing.com/free-visio-bpmn-modeler" rel="nofollow">http://www.interfacing.com/free-visio-bpmn-modeler</a>. But I want to create my own icons(notations) and make it domain specific. Please help me? How can I do this? What languages do I have to use?</p>