pdfTeX is a variant of the TeX typesetting program originally written by Hàn Thể Thành. The main difference between TeX and pdfTeX is that whereas TeX outputs DVI files, pdfTeX outputs PDF files directly. This allows tight integration of PDF features such as hypertext links and tables of contents, using packages such as hyperref. On the other hand, packages which exploit the usual conversion chain of DVI-to-PostScript such as pstricks may fail, although replacements such as pdftricks have been written.

It is possible to obtain DVI output from pdfTeX, when the output should be identical to that of TeX. Moreover, since LaTeX, ConTeXt et al are simply macro packages for TeX, they work equally well with pdfTeX. Hence, pdfLaTeX, for example, calls the pdfTeX program using the standard LaTeX macros to typeset LaTeX documents, whereas the --pdf option of texexec does the same for ConTeXt documents.

Features

pdfTeX has several features not available in standard TeX.

• native TrueType and Type 1 font embedding
• micro-typographic extensions such as margin kerning using font expansion
• direct access to pdf specific features such as hyperlinks, tables of contents and document information

References

• Micro-typographic extensions to the TeX typesetting system (http://www.pragma-ade.com/pdftex/thesis.pdf) - dissertation by Hàn Thể Thành
• pdfTeX distribution at TUG.org (http://www.tug.org/applications/pdftex/)
• pdfTeX source code (ftp://ftp.cstug.cz/pub/tex/local/cstug/thanh/pdftex/)