Carbon is a set of components + awesome hacks built to help web developers speed up their proccesses by letting them build sites with tailor-made UI components.
Carbon is the main chemical element found in life. So, the Carbon Framework is the main framework found in all of our sites.
We used SASS and JS to develop most of the core components, and we built the whole thing so that it runs smoothly over Bootstrap 4 (Twitter Bootstrap is not 100% required, but some components are built to work only with Bootstrap).
You can check our documentation here.