CodePen is a playground for the front end side of the web. It's all about inspiration, education, and sharing.
Need to build a reduced test case to demonstrate and figure out a bug? CodePen is great for that. Want to show off your latest creation and get feedback from your peers? CodePen is great for that. Want to find examples of a particular design pattern for your project? CodePen is great for that.
CodePen PRO takes things further with features like Collab Mode which allows you to pair program in real time and Professor Mode for allowing a group of students to follow you as you teach code and chat with each other.
The three of us met in Florida as we were the first three design/development hires at Wufoo. We then all moved to California when Wufoo was bought by SurveyMonkey, where Tim and Alex were DevOps developers. We are all equal co-founders of CodePen.