On 2013–02–22 hwitloc@gmail.com wrote:

>   I use the ConTeXt which comes in TEXLIVE 2012, which I assume uses Mark IV.  Does that mean that I can not use this version of ConTeXt with XeteX which also comes packaged in TEXLIVE?

You can use MkII with XeTeX as follows:

  context --xetex file.tex

Marco