Hz-program

The goal of this program was: "To produce the perfect grey type area without the rivers and holes of too-wide word spacing.

"[citation needed] In a 1993 essay, Zapf explained the history of Hz-program, which included work at Harvard University prior to his current work at the Rochester Institute of Technology, the first university in the world to establish a chair for research and development on the basic structures of typographic computer programs.

According to Zapf,[3] Hàn Thế Thành made a detailed analysis of the Hz-program for microtypography extensions to the TeX typesetting system and implemented them in pdfTeX.

[1] The particular technique of condensing and expanding characters (glyph scaling) which is an essential part of the Hz-program, and which is now an option in Adobe InDesign and pdfTeX, has aroused critique from well-known designers like Ari Rafaeli.

[4] Typographer Torbjørn Eng has raised serious doubts about the validity of referencing the glyph scaling to Gutenberg.