I need a piece of software to allow me to create XML from a DTD. I don't want to have to see the actually XML at all though. I would like something that generates a GUI based on the DTD and allows me to edit from there. Is there anything like this out there?
You absolutely need to checkout oxygen ( http://www.oxygenxml.com/). I use it everyday for xml documents that are use schema. Osygen does everything from auto complete to XML tree editing and does drop don selection for schema element enumeration. There is also a lot of support for DTD as well. I have used several different editors and nothing compares
It's not exactly what you asked for, but it might still be able to do it: XMLMind. It does a lot of really nice things, including fully graphical XML editing with no markup visible, and you can create your own GUIs for particular document types using extended CSS. Although it's primarily oriented towards document editing, it can also be used for data-oriented XML. For example, I'm using it to maintain my address book.
If you register the DTD with it, it can create new documents of that type, containing the minimum allowed by the DTD. However, if you want to create sample documents that contain examples of everything possible in the DTD, you do better with a tool like Oyxgen, as already mentioned. It too has an authoring mode, for wysiwyg content creation, although I haven't used that part of Oxygen enough to compare it with XMLMind.
You might find what you're looking for in a related StackOverflow question.
The NetBeans IDE has a pretty solid XML/XSD/DTD support with nice visual tools and easy switching between source and design views.
It's excellent and free - I actually prefer it to the commercial XMLSpy product.