Does anyone know what (if any) open source assemblers exist, that are written in Z80 assembly themselves? I'm aware of: proprietary ones like GEN80 (my fav way

Does anyone know what (if any) open source assemblers exist, that are written in Z80 assembly themselves? I'm aware of: proprietary ones like GEN80 (my fav way back), M80/L80, at least one open source assembler written in plain C, and probably some table-driven assemblers targeting multiple architectures.