This is old news. Is there some reason this link has been posted ? What does @aegean wish to discuss.
I've used YAML quite a bit. However, unlike XML, content can get jumbled if there are say "-" inside a field. Complex content won't work with YAML. I once came across a ruby website builder that used YAML for its pages (i think it was called hobix, in the days of _why/redhanded). The YAML would get saved to a file, but when reading it would throw errors due to the content within a field.
So i ditched YAML and used pstore (unfortunately this is ruby specific and not a text file). XML has CDATA or similar tags to mark such data.
