\documentclass{minimal}
\usepackage{logreq}

% biblatex example
% (this is a mockup of code which will be used in biblatex >= 0.9b)

% sample preamble:

% \usepackage[latin9]{inputenc}
% \usepackage[american]{babel}
% \usepackage[style=authoryear,backend=bibtex8,mincrossrefs=1,bibencoding=inputenc]{biblatex}
% \bibliography{bibfile1,bibfile2,bibfile3}

% workflow:

% latex file	(-> both requests active)
% bibtex file
% latex file	(-> both requests inactive)

% additional bibtex passes may be required to resolve xrefs,
% additional latex passes may be required to resolve labels;
% i.e., the workflow may get as complex as this:

% latex file	(-> both requests active)
% bibtex file
% latex file	(-> both requests active)
% bibtex file
% latex file	(-> latex request active, bibtex request inactive)
% latex file	(-> both requests inactive)

\logrequest[package=biblatex,priority=5,active=1]{
  \generic{bibtex}
  \cmdline{
    \binary{bibtex8}
    \option{--wolfgang}
    \option{--min_crossrefs 1}
    \option{--csfile latin9.csf}
    \infile{\jobname}
  }
  \input{
    \file{\jobname.aux}
  }
  \output{
    \file{\jobname.bbl}
  }
  \provides[type=dynamic]{
    \file{\jobname.bbl}
  }
  \requires[type=dynamic]{
    \file{\jobname.aux}
    \file{\jobname-blx.bib}
  }
  \requires[type=editable]{
    \let\do=\file
    \docsvlist{bibfile1,bibfile2,bibfile3}
  }
  \requires[type=static]{
    \file{biblatex.bst}
    \file{latin9.csf}
  }
}

\ltxrequest{biblatex}{1}{
  \provides[type=dynamic]{
    \file{\jobname.aux}
    \file{\jobname-blx.bib}
  }
  \requires[type=dynamic]{
    \file{\jobname.bbl}
  }
  \requires[type=static]{
    \let\do=\file
    \docsvlist{biblatex.def,authoryear.bbx,standard.bbx,authoryear.cbx,
               biblatex.cfg,american.lbx,english.lbx}
  }
}

\begin{document}
\end{document}