The development kit for over a hundred z80 family machines - c compiler, assembler, linker, libraries.

The original IBM PC and other machine emulations in JavaScript

PCjs Machines 1.0 (archived)

Command-line cross-compiler of assembly language for Z80 CPU.

A complete emulation of the Intel 8080 processor written in C99.

i8080 precise replica in Verilog, based on reverse engineering of real die

Online 8085 simulator

The famous Intel 8080 CP/M 2.2 to Intel 8086/8088 MS-DOS assembly language translator.

Z80 / 8080 / Z180 assembler (for unix-style OS)

Awesome Lists of retrocomputing resources (6502, Apple 2, Atari, ...)

Fast and flexible Z80/i8080 emulator with C++ and Python APIs

Single header Z80 emulator for C++ (C++11 or later)

retrohunblog

A Space Invaders emulator written in C99 with the SDL2 and SDL2_mixer.

CP/M and MS-DOS COM executable linker written in D.

Whitesmiths C compiler. One of the earliest commercial C compilers available.

SB-Assembler Version 3 - Cross Macro Assembler

pmince: Portable MINCE (MINCE is Not Complete[ly] EMACS)

Zilog Z80 and Intel 8080 emulator library for Rust that passes all ZEXALL tests

Emulators for 8080/8085, 8086/8088, Z80, 6502 and TMS1000-family CPUs