I'm wondering what the difference is as I've never heard these distinctions? I've worked with many different commercial engines professionally and they basically consist of a WYSIWYG level design tool (along with various other asset tools/conditioners) and then a scripting language (or some type of visual scripting tool like Kismet or C4 incorporates) and sometimes customizations in C++ either as a plugin or core to the build. The vast majority of games are built using a technology like this.
WYSIWYG engines are perfect for beginners, API-style engines... not so.
Mind you I'm not arguing or saying there isn't such a distinction, it's just that I've never heard of it.