It isn't a framework, it is a concept that would allow you to build a framework of your own design.
Just like plugins only allow you to build plugins and themes really allows you to build themes. Really there are not any plugins or themes that come with it, which is what a completed framewould would generally include.
You can think of these extensions as organizational tools and concepts that are meant to help you organize, and modularize your code for easier re-use, manipulation, and long term maintinance by the nature of the improved organization.