There are 2 repositories under z80asm topic.
A simple text-based adventure game
Support for Z80 macro-assemblers in Visual Studio Code
Стартовый набор для вхождения в разработку под ZX Spectrum // A set of software, source codes, literature, utilities, and a build system for entering development for ZX Spectrum
The first Z80 emulation library for Arduino
half float library for C and for z80
Z80 libraries for the Sega Master System
Skeleton C (sdcc) project for MSX binaries
A fast Forth Standard system written in Z80 assembly for SHARP PC-G850 pocket computers
a BASIC interpreter for CP/M and the RetroBrew SBC v2, based on the Z80 port of Palo Alto Tiny Basic
An audio driver for the NeoGeo written in Z80 assembly
Zalt is a home brew Z80 computer with a modern(isch) chipset.
Instant ZX-SPECTRUM - best emulators, software collection, ZXBOX VM build
Upgraded S3&K sound driver
My MSX basic and assembly programs
Network neXt Time Protocol. Server in .NET Core, Clients for ZX Spectrum Next™ and .NET Core.
Reverse engineering games using SkoolKit
Robot Poncots (ロボポン) Sun and Star (Japanese)
An hello world for Game Boy made with GBZ80 asm
Assembly MSX Z80 Code for ROM Games by ThePetsMode using ASMSX assembler
A C library for using the TMS9918A video board on a RC2014 retrocomputer.
Various plugins for CSpect, an emulator for the ZX Spectrum and ZX Spectrum Next™
FantASM - A Z80 assembler
Snake clone written in Z80 assembly for the ZX Spectrum
Monitor program for the Calculon/80 microcomputer
Repo containing the Pix80's OS and Documentation, alongside example Programs