BirdFont — birdfont.org ↗
DTL LetterModeller— dutchtypelibrary.nl ↗
Glyphs — glyphsapp.com ↗
FontForge — fontforge.org ↗
FontLab — fontlab.com ↗
Fontself — fontself.com ↗
Fontra — fonttra.xyz ↗
RoboFont — robofont.com ↗
RoboFont Mechanic — robofontmechanic.com ↗

FontBase — fontba.se ↗
Typeface — typefaceapp.com ↗

Anatomy of a Character — myfonts.com/pages ↗
Diacritics — diacritics.typo.cz ↗
Dinamo Font Gauntlet — fontgauntlet.com ↗
FontDrop! — fontdrop.info ↗
FontGoggles — fontgoggles.org ↗
Unicode — unicode.org ↗
Wakamai Fondue — wakamaifondue.com ↗

Source Han Serif — source.typekit.com ↗

@Font-Face generator — Transfonter.org ↗

BIG TYPE — bigtype.xyz ↗

Drawbot — drawbot.com ↗
TypeCooker — typecooker.com ↗

Adobe Type and type technology resources — helpx.adobe.com ↗
Microsoft Typography — learn.microsoft.com ↗

Identifont — identifont.com ↗

KernType — type.method.ac ↗
ShapeType — shape.method.ac ↗
The Bézier Game — bezier.method.ac ↗