It's hard to find a good Qt application built to document good practices. The Qt examples are great, but they are small and built to highlight a single feature. New Qt coders are constantly asking how to build applications - what goes where and how?
Great Qt code is easy to find in the numerous applications available, and the open source applications are good to look at from a learning point of view. The difference between this editor and those other applications is that we have tried to keep the application logic as small as possible - which is of course the direct opposite of a real application.
It's equally hard to find a good example Qt and CMake together. Of course, QMake is an obvious choice for Qt software, and is in many places much easier to use than CMake. But when it comes to power and features, CMake has an advantage on QMake. CMake can do much more than QMake, but at the price of a harder build language. We normally use QMake and QtCreator, but when this isn't the case, CMake is the preferred choice.
The FS Editor was created to show an example of how a big software system can be done with Qt, and how you build it with CMake. The focus is on architecture and on showing how features are done, so the editor itself is almost useless - pretty much on the level of Notepad.
The one thing we don't want is to develop this into a full fledged editor. Because that would hide all those architecture details we're trying to show. If you want to work on this editor, feel free to fork it and use it in any way you like.
The package doesn't come with any documentation. Instead, there are some blog entries about this software. See the Qt blog for all the articles.
The license of this software is public domain. You can do with it what ever you want.