Apple dfont

Apple Data Fork Font (dfont) is a legacy Mac OS X format.

Overview

• Container: Resource fork format in data fork
• Font Types: TrueType, OpenType, or mixed
• Platform: macOS specific

Structure

dfont uses resource fork structure:

• Resource map
• Resource data
• Multiple font resources

Loading

font = Fontisan::FontLoader.load('font.dfont')

# Access as collection
if font.respond_to?(:each)
  font.each do |f|
    puts "#{f.family_name} #{f.style}"
  end
end

Extracting

CLI

# List fonts in dfont
fontisan ls font.dfont

# Extract all
fontisan unpack font.dfont --output-dir ./extracted

API

dfont = Fontisan::FontLoader.load('font.dfont')

dfont.each_with_index do |font, index|
  output = "font-#{index}.ttf"
  Fontisan::FontWriter.write(font, output)
end

Converting

dfont to TTF

fontisan convert font.dfont --to ttf --output font.ttf

dfont to OTF

fontisan convert font.dfont --to otf --output font.otf

To dfont

# From TTC
fontisan convert family.ttc --to dfont --output family.dfont

# From individual fonts
fontisan pack regular.ttf bold.ttf --output family.dfont

Limitations

• macOS only — Not cross-platform
• Legacy format — Modern formats preferred
• Limited support — Some tools don't read dfont

When to Use

• Legacy Mac fonts — Converting old resources
• Resource fork recovery — Extracting embedded fonts
• macOS compatibility — When required

Modern Alternatives

For new fonts, prefer:

• TTC — TrueType Collection
• OTC — OpenType Collection
• WOFF2 — Web delivery