Similar to OpenRC

Fast Library for Number Theory

Ffdshow

FFmpeg

Fastest Fourier Transform in the West

Firebird (database server)

Firewalld

Flask (web framework)

Flatpak

FLTK

Flutter (software)

FMSX

Foliate (software)

FontForge

Foresight Linux

Fossil (software)

Free Pascal

FreeBASIC

FreeMat

FreeSBIE

FuelPHP

FVWM