tweaklist.sty

\def\enumhook{}
\def\enumhooki{}
\def\enumhookii{}
\def\enumhookiii{}
\def\enumhookiv{}
\def\itemhook{}
\def\itemhooki{}
\def\itemhookii{}
\def\itemhookiii{}
\def\itemhookiv{}
\def\descripthook{}
\def\enumerate{%
  \ifnum \@enumdepth >\thr@@\@toodeep\else
    \advance\@enumdepth\@ne
    \edef\@enumctr{enum\romannumeral\the\@enumdepth}%
      \expandafter
      \list
        \csname label\@enumctr\endcsname
        {\usecounter\@enumctr\def\makelabel##1{\hss\llap{##1}}%
          \enumhook \csname enumhook\romannumeral\the\@enumdepth\endcsname}%
  \fi}
\def\itemize{%
  \ifnum \@itemdepth >\thr@@\@toodeep\else
    \advance\@itemdepth\@ne
    \edef\@itemitem{labelitem\romannumeral\the\@itemdepth}%
    \expandafter
    \list
      \csname\@itemitem\endcsname
      {\def\makelabel##1{\hss\llap{##1}}%
        \itemhook \csname itemhook\romannumeral\the\@itemdepth\endcsname}%
  \fi}
\renewenvironment{description}
                 {\list{}{\labelwidth\z@ \itemindent-\leftmargin
                          \let\makelabel\descriptionlabel\descripthook}}
                 {\endlist}