Why non-free license?

[Maniues]

Is there any chance that the specification (and other related projects such as the reference parser) will be released under an open license?

I don't fully understand the attempt to limit specification modifications through licensing. There are many other specifications that can be freely changed without any ill effects.

[mooreb]

Under what license is the yaml spec published?

[Maniues]

This document may be freely copied, provided it is not modified.

[UnePierre]

Just a suggestion: if you come across a good solution for a change to said license, how about proposing a pull request?

Just a guess: as long as the team (of which I'm no part) is working on two specs at the same time and doing complicated refactoring (as far as I understand), maybe they want to cut down on the tedious work of unifying spread-out different versions of their work? I mean, I can understand if they want to choose a good level of specification first.