www.logiccircuit.org

I am trying to add new gate types under a new Category. They show up in the list under the new category but their glyph is not displayed, thus can't be dragged and dropped. I also noticed the xsd files or the metamodel are not in the downloaded solution.

Hi,
Right now there is only one way to change category of the circuit. First you need to make it current by double click it in the left panel. Then you click menu Circuit/Logical Circuit. This will bring properties of current logical circuit and then type or select category in the dialog. After you click OK button in the dialog your circuit will be moved to the appropriate category.
However your idea of drugging and dropping symbol between categories looks very good and will be implemented in future version.
Thanks,
Eugene