<texcode>
\startmode[palatino]
\usetypescript[palatino][8r]
\setupbodyfont[palatino,12pt]
\stopmode
\startmode[times]
\usetypescript[postscript][8r]
\setupbodyfont[postscript,12pt]
\stopmode
and run with one of the following:
texexec context --mode=palatino filename texexec context --mode=times filename
== Running external commands once ==