FontForge

FontForge is a free (libre) font editor for Windows, Mac OS X and GNU+Linux.
Use it to create, edit and convert fonts in OpenType, TrueType, UFO, CID-keyed, Multiple Master, and many other formats.

fontforge.org — homepage

designwithfontforge.com — font creation manual

INSTALL-git.md — developer instructions to build from source

.travis.yml — a list of installation dependencies

CONTRIBUTING.md — contributing guidelines