A free Windows-compatible Operating System

Vifm is a file manager with curses interface, which provides Vim-like environment for managing objects within file systems, extended with some useful ideas from mutt.

rusefi - GPL internal combustion engine control unit

Exim Mail Transport Agent - source, testsuite and documentation

The classic, refined DOOM source port. For Windows PC.

GPL Electronic Design Automation

Frosted: Free POSIX OS for tiny embedded devices

An extended fork of GNU Unifont with a focus on high compatibility.

UNIX-like operating system written in C and C++

x86-64 kernel for learning purposes

A TUI Pager for Markdown, a tool similar to man(1) or most(1), but renders Markdown in-terminal

Quake Essentials. Better than what a licencee of id would get in 1996. For even more goodness to base your game off of, see https://github.com/VeraVisions/nuclide

A GTK+ interface for PHP's built-in web server

Source code for Norton's Core router.

An implementation of Zephyr ASDL in C, targeting C

Open source Breakout-style game for PalmOS devices, written in C with a little 68k assembly. First released in 2003.

⚙️ A Windows boot loader that replaces Microsoft's boot loader

NetCDF bindings for PHP

Sistema operativo libre y colaborativo, donde todos pueden contribuir.

GNU GPL container for embedded devices