amoeba OS
Independent-desktop OS
skiftOS
Atari DOS – Atari Projects
TRSDOS Commands
Sineware ProLinux 2
sphaerophoria/stream-os · GitHub
IBM z/OS operating system
vinsdragonis/Odin · GitHub
araujo88/primus-os · GitHub
minexew/Shrine: A TempleOS distro for heretics
cia-foundation/TempleOS · GitHub
Oro Operating System
alexdboxall/Banana-Operating-System · GitHub
KotOS
FoxOS
Greentea OS
pranaOS/pranaOS · GitHub
aura-systems/Aura-Operating-System · GitHub
AROS Research Operating System
FlingOS
opuntiaOS-Project/opuntiaOS · GitHub
Zeal-Operating-System/ZealOS · GitHub
KolibriOS
meanOs - The smallest and the most powerful operating system
ReactOS
Inferno
Commodore 64 OS
FreeDOS-32
ToaruOS
skiftOS