I personely collect weird, crazy and curious operating systems and here you can finde some of them. Not all of them are real and some are total hoaxes but some are important for the history of operating systems and personal computers.

So let’s dive in into the Rabbit Hole!

Red Star OSNational OS of North-Korea1
JesOS™Unknown OS – no informations1
TempleOSKind of religion OS by Terry A. Davis1, 2
Muslim-OSLinux based OS for muslim users. Similar to SabilyOS1
UOSNational OS supported by Chinese authority1
KylinOS developed by National University of Defense Technology China1
NovaNational OS supported by Cuba’s authority1
MOSSoviet clone of Unix System1
Astra LinuxNational OS supported by Russian authority1
AmigaOSNative OS for the Commodore Amiga1
Zamin OSNot verified – National OS of Iran1
NeXTSTEPHybrid OS from the 1980s and 1990s1
UniOSFake/Hoax OS from a german student1
MenuetOSLightweight OS written in assembly – It fits on a single floppy1, 2
OpenVMSEarly OS from 1977 for VAX computers1
RodosReal-time OS developed and used by the DLR1, 2
VxWorksReal-time OS used by NASA for the Pathfinder-Mission1, 2
COSChinese national mobile OS developed by ISCAS1
COSMysterious OS as an alternative for the Apple Mac1, 2
COSNative OS for supercomputer from Cray Research 1
BeOSAlso known as Media OS by Be Incorporated – 2001 sold to Palm, Inc.1
OS/2Developed by IBM and Microsoft – original successor for DOS1
Domain/OSNative OS for Apollo/Domain workstations by Apollo Computer1
Buddha OSUnknown OS – no informations1
Symbian-OSNative OS for Nokia Phones and PDAs1
Lisa OSNative OS on Apple Lisa in 19831

Here is also a list of all Robotron operating systems. Unfortunately, there are too many of them.