Hi! I am trying to get a bit of an overview of how to implement custom features into ISPConfig. The documentation is rather sparse, and the only real tutorial I found is this: http://docs.ispconfig.org/development/interface/ My questions are: 1. Is this documentation still relevant for 3.1 or are there major changes in how to implement the module discussed there? If there are changes, are they documented somewhere? 2. Are there any other resources to learn developing modules/plugins? Maybe an already implemented extension which can serve as a good example? Any recommendations? 3. If i write a module (like the one in the tutorial from 1.) will it be overwritten when I update ISPConfig? Generally it would be nice to know how easy it is to extend ISPConfig without hacking the core, and having to reimplement stuff after every upgrade. I know that is a rather "broad" question though.. Thanks!