From the homepage:
The following ConTeXt mode is no longer needed; ConTeXt support is now built in AUCTeX (at least developer version).
License: ConTeXt is distributed in a more-or-less “do-what-you-like” license, expressly intended to be GPL-compatible and in GPL spirit, as well as compatible with the TeX license, See http://www.pragma-ade.com/general/manuals/mreadme.pdf
See also: ConTeXt wiki