From ConTeXt wiki

By default, choosing the ConTeXt option from the drop-down executes

 texmfstart texexec <filename>

which executes ConTeXt using pdfTeX; the XeConTeXt option executes

 texmfstart texexec --xtx <filename>

which uses XeTeX.

Adding an option to use ConTeXt with LuaTeX

  • In the menu select Edit > Preferences...
  • Go to the Typesetting tab
  • On the Typesetting tab, the "+" button at the bottom right lets you add new compilation options.
  • To typeset with MkII and the LuaTeX engine:
    • Program: texmfstart
    • Parameters: texexec --lua $fullname
  • To typeset with MkIV (which always uses LuaTeX):
    • Program: mtxrun
    • Parameters: --script context --synctec $fullname