LarsXYZ wrote: Finally I succeeded with the StringBuilderVisualizer, which loads automatically. It works fine with a listbox, I just had to discover how to activate it That is great news I had the same sort of problem when I started using visualisers. Next since you are starting out I would suggest you get to better know the full power of Visual Studio and download the Visual Studio SDK and look at the examples. Also take a look at DSL's they provide a way to design and develop an architecture specific to a horizontal or vertical market and much more. Also look into T4 it's a powerful code generating template that you can embed .NET in and reuse in many other projects and create specific types of start-up projects. :-\ ~TheArch "Make everything as simple as possible, but not simpler." -- Albert Einstein "It didn't matter to us whether people believed in us. We believed in ourselves. We had the courage to follow our own path." ~~Nvidia's Jen-Hsun Huang