We're beyond excited to finally be able to release this! Many, many months of work now bring us CodePen PRO with 8 all new features.
You can go read about them in the documentation, but just to give you a taste, one of them is Collab Mode. It is pretty incredible, if you ask me. Multiple people can type into the code editors at the same time, and see the live preview below. This isn't some hokey, half-assed collab mode where the editors lock or only one person can really be working at any given second. We use all kind of fancy merging, diffing and math (math!) to keep everyone in sync.