Deprecated
Unfortunately YouTube decided that this project does not align with their terms per policy I.1:
I. Additional Prohibitions
...
You and your API Clients must not, and must not encourage, enable, or require others to:
- use YouTube API Services to create, offer, or act as a substitute for, or substantially similar service to, any YouTube Applications. API Clients must not mimic or replicate YouTube's core user experiences by recreating features or process flows unless they add significant independent value or functionality that improves users' interactions with YouTube. For example, an API Client must not recreate the browse experience from any YouTube Application without adding significant independent value to that flow.
While I disagree with this statement - seeing network of YouTube videos is not possible on YouTube itself I have no power to overrule their verdict.
It was a fun project and you can see how it used to renders graph of related YouTube videos:
MIT