When KSP was first released, all those years ago, there wasn't any toolbar, so @blizzy78 made the very popular toolbar which many mods use. Then KSP released the stock toolbar.  Many people like and use the stock toolbar, and many like and use the Blizzy toolbar.  Both have advantages and disadvantages. Most if not all of my mods allow the user to use either one.  I got tired of recoding the toolbars for every mod, and came up with this mod to make life much easier, and wrote an interf