update: 8/10/2013. This below is no longer needed. htlatex now includes support directly for multicols. I kept this below for archive purpose, do not use. See this instead
http://tug.org/pipermail/tex4ht/2013q3/000847.html
see http://tug.org/pipermail/tex4ht/2013q3/000828.html
Using this my.cfg.txt file as an example
\Preamble{ext=htm,pic-align} \begin{document} \EndPreamble \catcode`\:=11 \catcode`\@=11 \Configure{HtmlPar} {\EndP\HCode{<!--l. \the\inputlineno-->% <p \csname a:!P\endcsname class="no\ifHCond par\else indent\fi" \a:LRdir>}} {\EndP\HCode{<!--l. \the\inputlineno-->% <p \csname a:!P\endcsname class="\ifdim \parindent=\z@ no\fi indent" \a:LRdir>}} {{\Tg</p>}} {{\Tg</p>}}% \renewenvironment{multicols}[1]{\IgnorePar\EndP% \HCode{<div class="newspaper}#1\HCode{">} \expandafter\ifx\csname .newspaper#1\endcsname\relax% \Css{.newspaper#1 p:first-child { margin-top: 0em; }} \Css{.newspaper#1 { -moz-column-count:#1; /* Firefox */ -webkit-column-count:#1; /* Safari and Chrome */ column-count:#1; -moz-column-gap:10px; /* Firefox */ -webkit-column-gap:10px; /* Safari and Chrome */ column-gap:10px; -moz-column-rule:1px outset \#F8F8F8 ; /* Firefox */ -webkit-column-rule:1px outset \#000000; /* Safari and Chrome */ column-rule:1px outset \#000000; }} \expandafter\gdef\csname .newspaper#1\endcsname{1}% \fi% \ShowPar\par} {\EndP\HCode{</div>}} \ConfigureEnv{multicols} {\par\IgnorePar\EndP% \gHAdvance\MultiCols by 1\relax} {\ifvmode\IgnorePar\fi\EndP} {}{} \endinput
and using this Latex file as an example foo.tex
\documentclass{article}% \usepackage{lipsum} \usepackage{multicol} \setlength{\columnsep}{20pt} \setlength{\columnseprule}{0.01pt} \begin{document} \begin{multicols}{2} \begin{enumerate} \item A \item B \end{enumerate} \lipsum[1-10] \end{multicols} \end{document}
and using this command htlatex foo.tex "my.cfg" then htlatex will generate multiple
columns.
Thanks goes to Jagath AR for help in greatly improving the configuration file.