Eplain redefines the \TeX
macro of plain TeX to end with \null, so that the proper
spacing is produced when \TeX is used at the end of a sentence.
The other ...TeX macros listed here do this, also.
Eplain defines
\AMSLaTeX,
\AMSTeX,
\BibTeX
\eTeX,
\ExTeX,
\LAMSTeX,
\LaTeX,
\MF,
\SLiTeX,
\XeLaTeX,
and \XeTeX
to produce their respective logos. (Sorry, the logos are not shown
here.) Some spelling variants of these are also supported.
Most of these macros come from texnames.sty, compiled by Nelson Beebe and available at http://www.ctan.org/tex-archive/info/biblio/texnames.sty.