[espadrine]

What makes you say that? The description seems pretty specific about the end result being open-source and distributed as a gem.

EDIT: indeed, the $50-backers description alerts of a rise to $100 after the kickstarter. That has to be a huge mistake on their part.

EDIT 2: I just received information from Tom Black that the software environment, along with the lessons, challenges, projects, will be free and open-source. What will be paid are subsequent, related screencasts and online classes.