Unlike a typical CMS, a CMF is geared more towards configurability and customization. Picture a range of measurement where one end of the scale is labeled “specific” and the other end “abstract”. On the “specific” end of the spectrum, you would have something whose form is very specialized because it’s meant for a specific purpose—like, say, a hammer. On the other end of the spectrum, you would have something much more abstracted, that is available to be configured any way you like, for a variety of purposes—like some wood and a chunk of steel. You could make a hammer, or any number of other things with the wood and steel. Of course, while chunks of wood and steel are more “configurable” than a hammer, they aren’t terribly useful because few people have the specialized knowledge to work with such raw materials.
Below is a list of notable systems that claim to be CMFs.