The packagers of the tetex-latex package have left out the foils class,
which is very interesting for the composition of slides. The corresponding
documentation is also missing from tetex-doc.
It's not allowed for commercial distribution, so it was removed.
Get the RedHat 6.0 package tetex-latex-0.9-17.i386.rpm (from rpmfind.net or
elsewhere), and extract /usr/share/texmf/tex/latex/foiltex/* manually with mc,
and then rebuild the ls-R database using texconfig.