Charles Poynton -
Document formats

I make many of my documents available in HTML form. For documents whose content depends on typographic presentation and/or on illustrations, I distribute Acrobat PDFformat. Details on PDF format, and a few other formats, is presented here.

PDF - Portable Document Format - .pdf

I'm an Adobe Acrobat fan. Acrobat uses Portable Document Format (.pdf) files. Freely-distributable Acrobat Readers are available for Macintosh, Windows, MS-DOS and UNIX. PDF files can be viewed on-screen and printed to PostScript or non-PostScript printers without regard for which fonts are installed on your system. Version 3.0.2 for the Mac is in the file ar302.bin at Adobe's ftp site (MacBinary format, 5581952 bytes). Version 4.0 for the Mac is in the file ar40eng.sit.bin at Adobe's ftp site (MacBinary format, 4175232 bytes).

Netscape has integrated PDF viewer technology within version 3 (and higher) of the Netscape browser, so it is easy to use PDF with the web. Personally, I despise the user interface. Five (!) window titles - the menu bar, the Netscape window title bar, Netscape's buttons (or icons, or both), the URL line, then an Acrobat viewer toolbar - all in addition to whatever navigation aids might already be present in the PDF document! But there's no accounting for style on the web. I disable the Plug-in, and instead use the Acrobat Reader - actually, Acrobat Exchange, since I am licenced for the commercial Acrobat version 3 package. Adobe tells you how to configure Netscape to view PDF.

The best way to get Acrobat is to access Adobe's web site. The Adobe server is very reliable, but there are mirror sites.

If you transfer an Acrobat PDF file to a Windows or MS-DOS machine, transfer in binary mode. Although a version 1.0 of the PDF format was advertised as being 7-bit ASCII and "platform independent," in fact a PDF file contains coded  byte offsets. If you transfer in ASCII (text) mode you will alter the lineends from one character (CR or LF) to two (CR/LF) and thereby disturb the offsets. The Reader will rebuild them, but not before frightening you with a "File damaged" alert. Binary mode is now formally part of the PDF 1.1 standard (and its successor versions). Binary mode was formerly deprecated by Adobe, but starting with PDF-1.1 (corresponding to version 2 of the Acrobat products), Adobe is encouraging the use of binary PDF files. This gives you all the more reason to transfer in binary mode.

Phil Smith has written an excellent, short note Noddy's Guide to PDF.

PostScript - .ps

These files can be printed with a PostScript printer and viewed on most UNIX platforms. To learn more about PostScript, read Allen Braunsdorf's PostScript FAQ. Most of the PostScript files here have no embedded fonts and require only Times, Helvetica, Palatino and Symbol from the core 35 ("LaserWriter Plus") set of fonts that are built-in to almost all PostScript laser printers. The PostScript files use generic PPDs and are laid out with generous margins for US Letter size paper. I confess I don't know how well they print to A4.

If you are running Windows, UNIX or VMS, you can view PostScript using GhostScript or GhostView. You can obtain GhostScript from

You can view and print PostScript on a Macintosh using Mac GhostView. Version 5.5 is available. See my archaic page Viewing PostScript on a Macintosh.

Gnu zip Compressed - .gz

Many of the PostScript files on my ftp server are compressed using gzip ("gnu-zip"), a publically-available compression package. You can obtain various versions of the gzip program, including its source code, by anonymous ftp from the following locations:

Gnu zip replaces the traditional UNIX compress program. The major advantage of Gzip over compress (.Z) is that it has no patent infringement strings attached - UNISYS claims a patent on the LZW compression algorithm upon which compress is based.

If you use a Macintosh, Aladdin's latest StuffIt Expander (freeware) will decode these files. It is available at all the usual Mac repositories. You can download the freeware StuffIt Expander 5.5 from Aladdin's ftp site (MacBinary format, 824704 bytes) or the AOL mirror (MacBinary format, 824704 bytes). Aladdin's DropStuff with Expander Expander 5.5 (shareware, $30) adds to StuffIt Expander additional decoding capabilities such as gnu zip. Obtain it from Aladdin's ftp site (MacBinary format, 2049920 bytes) or the AOL mirror (MacBinary format, 2049920 bytes).