HTML Code Object
There isn't much to say or show about this. It lets you write or copy and paste HTML code directly onto your page. Technically speaking it creates an iframe which contains and executes the code you add to it.
This can be a very useful thing, for example I have used them on my learn python pages to embed working, editable python programs on the page (There's one below just so you know what I'm on about). Anything that can be coded into a stand alone frame can be included.