I'm working on a Salesforce Application. The application contains some custom objects, one of which is Project. I have created a Visualforce page to manage these projects. We are also developing an extension. In the extension, a new custom field is added to the Project object. In the original package, I want to change the visualforce page to show whether the value of that field (if the extension is installed). So I need to check if the extension is installed, and if so, display afield from that extension.
Is there any way to do that?