The Glyph Bitmap Distribution Format (BDF) by Adobe is a file format for storing bitmap fonts. The content takes the form of a text file intended to be human- and computer-readable. BDF is typically used in Unix X Window environments. It has largely been replaced by the PCF font format which is somewhat more efficient, and by scalable fonts such as OpenType and TrueType fonts. Overview the current version of BDF is 2.2. No future revisions are anticipated. Earlier versions were referred to as the Character Bitmap Distribution Format. In 1988, the X Consortium adopted BDF 2.1 as a standard for X Window screen fonts, but X Windows has largely moved to other font standards such as PCF, Opentype, and Truetype. Version 2.2 added support for non-Western writing. For example, glyphs in a BDF 2.2 font definition can specify rendering from top-to-bottom rather than simply left-to-right. A BDF font file contains three sections: a global section that applies to all glyphs in a font; a section with a separate entry for each glyph; and the ENDFONT statement. Example This is an example font containing one glyph, for ASCII capital 'A'. This glyph is taken from the GNU Unifont. <nowiki> STARTFONT 2.1 FONT -gnu-unifont-medium-r-normal--16-160-75-75-c-80-iso10646-1 SIZE 16 75 75 FONTBOUNDINGBOX 16 16 0 -2 STARTPROPERTIES 2 FONT_ASCENT 14 FONT_DESCENT 2 ENDPROPERTIES CHARS 1 STARTCHAR U+0041 ENCODING 65 SWIDTH 500 0 DWIDTH 8 0 BBX 8 16 0 -2 BITMAP 00 00 00 00 18 24 24 42 42 7E 42 42 42 42 00 00 ENDCHAR ENDFONT </nowiki> In the above example, the global declarations begin with the "STARTFONT" line and end with the "CHARS" line. "STARTFONT 2.1" defines the version of this BDF file as version 2.1. "FONT -gnu-unifont-medium-r-normal--16-160-75-75-c-80-iso10646-1" defines the font family and face names as an X logical font description. "SIZE 16 75 75" defines this to be a 16 point font, with an X-axis resolution of 75 dots per inch (dpi) and a Y-axis resolution of 75 dpi. This is the norm under X Window. "FONTBOUNDINGBOX 16 16 0 -2" defines a bounding box for the font of 16 pixels wide by 16 pixels high, with the lower left-hand corner starting at x=0, y=-2. Note that although the bounding box is defined to be a 16 by 16 cell, this can be overridden for individual glyphs. The "A" glyph, for example, is only 8 pixels wide. "STARTPROPERTIES 2"