ArCon is integrated with Eclipse and supports model developers in following given architectural rules for the developed system. ArCon interprets an architectural metamodel, created in UML, and extracts rules. The extracted rules are applied in an analysis of the developed system model. ArCon currently supports the developer in a reactive way resulting in a list of issues presenting violations to the rules. The scope also includes a proactive way of supporting the developer by presenting only allowed options when adding new elements and element properties. ArCon utilizes the Eclipse GUI and target modeling tools/editors are for now Papyrus and Topcased.