Very Incomplete List of Notable Operating Systems

Mainframe Era:

• ATLAS (perhaps first “real” OS?)
• IBM 1401
• IBM 7090 / CTSS
• IBM System/360
• MULTICS

Minicomputer Era:

• VAX/VMS / OpenVMS
• TOPS-20
• Unix

Microcomputer Era:

• CP/M
• DOS
• Windows
• AmigaOS
• BeOS
• NetBSD / OpenBSD / FreeBSD
• Linux

Microkernels:

• Mach
• L4

Teaching and Experimental:

• Minix
• Plan 9 from Bell Labs
• Basekernel (by Prof. Thain)

Real-Time and Embedded Operating Systems

• QNX
• FreeRTOS
• ROS