PICSimLab is a realtime emulator for PIC, Arduino, STM32, ESP32, ...
Z80 shared library including some nice test-projects
Graphics mode console I/O for the TRS-80 Color Computer
An replacement of DXForth's xplgraph.scr library for CP/M
Sega system-16 emulator
A C Compiler/Editor for Retro 6809 Machines (Colour Computer/Dragon)
z390 Portable Mainframe Assembler and Emulator