DFONT is the standard font format for Mac OS X. It stores font properties in a data fork instead of a resource fork. That is a change from the original fonts used in Mac OS Classic, which used two data segments rather than one. You can find these font files in the /Library/Fonts/ of your Mac OS computer. The fonts in DFONT are True Type fonts, meaning all major operating systems support them and are universal types across systems. That is why no matter your word processor program (Google Docs, Microsoft Word, etc.), you will find the exact font choices. You can open DFONT files in Font Book or DfontSplitter. However, DFONT files do not work across platforms. The format is only available on Max OS X, although many wish Windows PCs could adapt this more efficient font file format.