pdfTeX

pdfTeX is an extension of TeX that can generate PDF directly, without first producing DVI or PostScript. It is commonly used through plain TeX and LaTeX workflows to typeset technical documents, books, articles, and papers where precise layout and stable output matter.

It is used by researchers, publishers, and developers maintaining TeX-based publishing pipelines. A distinguishing trait is its direct-PDF engine with microtypographic features such as font expansion and character protrusion, which help improve line breaking and overall typographic quality in PDF output.