ARKTEX is a preloaded version of TEX that permits faster use of a large
number of fonts.  To use ARKTEX, say .R ARKTEX instead of .R TEX; you run
them the same way.  ARKTEX also has more size for macros than regular TEX.
Your macro package should include an "\input texpre" to get the proper
list of fonts.

ARKTEX also refers to a macro package maintained by Arthur Keller, for
which the preloaded version is maintained.  The preloaded version of TEX,
however, may be used separately.  The macro package is on [TEX,ARK].
READ ARKTEX for more details.