I really like that they used TensorFlow and published their code in GitHub. It will help a lot of people like me, that are new in the field and want to learn more about generative models. Amazing work by the OpenAI team!
In theory everything OpenAI does will be available on GitHub or in some comparable form: that's the point of the organization. That's why it's called Open AI. So that we can all share the benefits, instead of just Google having it for themselves. Because we all know that's who's hording the AI progress.