The Glyph Bitmap Distribution Format (BDF) is a file format developed by Adobe Systems for storing bitmap fonts. It is a plain-text, human-readable format that describes the character set and the individual glyph bitmaps of a font. Each BDF file contains global font information, such as the font name, point size, and resolution, followed by individual character definitions. Each character definition includes the glyph's bounding box, its bitmap data represented as hexadecimal strings, and its character code. Because it is text-based, BDF files are relatively large compared to binary font formats, but they are highly portable and easy to edit or inspect without specialized software. Historically, BDF was widely used in the X Window System for displaying text on Unix-like operating systems. While modern systems have largely transitioned to scalable formats like TrueType (TTF) or OpenType (OTF), BDF remains relevant in embedded systems, retro-computing, and specialized display environments where simple, fixed-size bitmap fonts are required for performance or hardware constraints.