[NTG-context] Up-to-date documentation / tutorials. Where?

Hello community, I have been (unsuccessfully) hunting for up-to-date tutorials/documentation on ConTeXt/LuaTeX/METAPOST. What I find is sites that for instance end in 2011. documentation that is from 2013, or on Pragme-ADE a show-man.pdf PDF with an overview of documentation that doesn’t open any underlying document. Is there not a simple place to get all the up-to-date documentation? G