Fragaria is a syntax colouring editor view for Cocoa.
It is based on Smultron (now Fraise) and provides an easy means of embedding a simple code editor in your Cocoa application.
The Smultron original used CoreData document storage. This requirement has been removed. As long as your document model supports KVC you should be able to get it to work okay.
The code comes packaged as a framework and can be obtained from http://github.com/mugginsoft/Fragaria
The project also includes a trivial application that utilises the framework.