Ask HN: Could we create a knowledge map for programming?

I find the biggest challenge in becoming a better programmer is deciding what to learn next.

Khan academy has a knowledge map for its math curiculum: https://www.khanacademy.org/exercisedashboard.

I think a similar map could be very useful to find your way around the big world of programming, but I'm not sure where to start.

Do you think this is a good idea? I think it should exist as an open source project, so people from different areas of expertise could contribute to the map.