Perl script that automates the process of generating a LaTeX document by running pdflatex, xelatex, or lualatex (plus bibtex/makeindex for bibliographies and indexes) the correct number of times — LaTeX often needs 2-3 passes to resolve cross-references, tables of contents, and citations correctly, and latexmk figures out exactly how many are needed rather than requiring the author to guess. Also offers a continuous-preview mode that watches source files and reruns automatically on changes.