TIC-80 is a fantasy computer for making, playing and sharing tiny games.

Write a simple interpreter of C. Inspired by c4 and largely based on it.

A dynamic language and bytecode vm

cc65 - a freeware C compiler for 6502 based systems

The lcc retargetable ANSI C compiler

One true awk

The Computer History Simulation Project

A C Compiler that fits in the 512 byte boot sector of an x86 machine

Lisp in 99 lines of C and how to write one yourself. Includes 20 Lisp primitives, garbage collection and REPL. Includes tail-call optimized versions for speed and reduced memory use.

Portable Forth in C

Run DOS programs under linux:

Highly portable Zilog Z80 CPU emulator written in ANSI C

cbmbasic, a portable version of Commodore's version of Microsoft BASIC 6502 as found on the Commodore 64

SDK for developing with the llvm-mos compiler

Free Tektronix 4010, 4013, 4014 and 4015 terminal emulator for Raspberry Pi, Linux, macOS (Macintosh) and Windows

FreeDOS plus-plus, 64bit DOS

An SDK for developing DOS software for x86 machines, including IBM PC compatibles and NEC PC-98

An isomorphic BASIC language compiler for retrocomputers

Version 7 Unix for a POSIX world

Code from my book, "Tiny C Projects," published by Manning Inc.

Classic Colossal Cave Adventure

BASIC interpreter in lex/yacc/c

Easing the task of comparing code generated by cc65, vbcc, and 6502-gcc

Microemacs (aka uemacs) v2.0 text editor by Dave Conroy from 1985. Updated to compile on Windows and Linux.

a forth

FOCAL interpreter in lex/yacc/c