Use a webkit based editor with a complete api

Use Webkit as the editor widget. Right now with no complete editor widget it would be a few years most likely to create one from scratch mainly because of the layout engine that would have to be created. Webkit already has the layout engine, and a way to execute javascript in the context of the window.

I think that to incorporate a javascript/html based widget with a complete and simple API for accessing the document the application will be helpful in a few ways
- editor will be easily extensible by the user
- GTK part can handle the OS integration like contractor

This could work well, and provide a more manageable code base since a complete layout engine will not be necessary . Also to provide colors that match the user's theme there can be an interface in which the GTK part gives the JavaScript part all of the colors necessary.

The JavaScript API can provide a clean way to access the document as HTML, then in vala convert the html to whatever document format it needs upon saving.

Also going along with the concept provided by spiceofdesign there are two toolbars. The main toolbar which handles saving/loading and some document properties which could be in GTK. The secondary toolbar, the dynamic toolbar, could be handled on the JavaScript side since it is just for formatting what the user is typing.