Use mylatexformat.ltx to make a format based on the preamble of any LaTeX file. The use of formats helps to speed up compilations: packages which have been dumped in the format are loaded at very high speed. This is useful when a document load many packages (pgf-TikZ among other...) For the creation of the format use a command line like: etex -initialize [opts] "&pdflatex" mylatexformat.ltx """abc.tex""" mylatexformat.ltx has been primarily written from mylatex.ltx (available on CTAN under the contrib/Carlisle/ directory) but gets rid of many limitations or problems of mylatex.ltx. More precisely: - The format is created from the beginning of the file (usually \documentclass[...]{...} until either: ~ \begin{document} ~ \endofdump if \endofdump is encountered in the preamble ~ \csname endofdump\endcsname for convenience: to avoid `undefined control sequence' in case the document is compiled without the format. - \begin{document} \endofdump or \csname endofdump\endcsname can be precedeed or followed by other macros or commentaries. - Commentaries in the preamble are ignored (braces are not required to be equilibrated). - packages that modify the \document macro (like auxhook.sty or etoolbox.sty) can be included in the format. - A report is available in the .log file. I have been using mylatexformat.ltx with MikTeX under: - pdfTeX in dvi mode - pdfTeX in pdf mode - XeTeX Comments about its use on other system are welcome !