There are many different font formats that can play a role in an X11 system configuration. The following table summarizes some of the common formats:
The Bitmap Distribution Format (BDF) is the standard format for distribution of fonts. It is an ASCII format so it can easily be edited it with your favourite editor or E-mailed to other users. As the name suggests, it stores bitmap fonts only.
Another virtue of the BDF format is that most font format converters convert to or from this format. Means if you want to go from format A to format B, neither of which is BDF, then you are likely to convert A to BDF, then BDF to B.
The BDF format is defined by Adobe. A document describing the format is available by ftp from Adobe's file server at ``ps-file-server@adobe.com''. It is also available in the standard X distribution. Look under ../X11R4(5)/mit/hardcopy/BDF. This document is also reproduced in any text describing the X standard.
The Server Normal Format (SNF) is an older format for bitmap fonts. The format is X Server and host dependent. This means that if you have two SNF files, their actual format may be different. Also, if you have an ``snftobdf'' utility, it may not be able to read font files from other systems. Convert to BDF format before you move it off the host system.
Snftobdf is one utility that can generate a BDF file from a SNF file. It was part of the X11R4 contrib release. To compile under X11R5, you need some of the X11R4 snf include files.
The Portable Compiled Font (PCF) format is a binary format for bitmap fonts. The binary contains sufficient information to be readable by other systems.
These fonts are only applicable in PEX environments. PHIGS fonts don't really have any relationship to the normal X font mechanism.
The DECWindows Fonts (DWF) are bitmap fonts.
These are HP scalable fonts.
These are Adobe Type 1 PostScript fonts.
They can be used in X11R5 based X servers and font servers because IBM has donated a renderer for this format to the X Consortium. The renderer can be found on the X11R5 contrib, and on ftp.x.org.
This is a format from Bitstream, Inc. Bitstream has also donated a font renderer to the X Consortium, and a couple of fonts.
I have been told that in order to use commercial fonts from BitStream, you must patch the renderer somewhat to make it use the right decryption code for the font.
These are Sun X11/NeWS format bitmap fonts used by the Sun OpenWindows system.
You can use "convertfont" which comes with OpenWindows to convert to/from BDF.
This is the scalable Sun Folio format, also used by OpenWindows.
You can use "convertfont" to convert to (not from) BDF.