See also:

• Computers: Software: Operating Systems: Monolithic  (2)
• Computers: Software: Operating Systems: x86: DOS  (213)

• Concurrent Controls, Inc. - Makes, sells, supports Multiuser DOS, Concurrent DOS; helps businesses and VARs do more with less.
• Multiuser DOS - Growing article, with links to many related topics. Wikipedia.
• On Time Informatik GmbH - Makes, sells, supports RTKernel, realtime multitasking system for DOS; compact (about 16k code, 6k data); gives programmers the basic tools needed to develop efficient realtime software. No royalty.
• S&H Computer Systems, Inc. - Makes TSX-32 general purpose, multiuser, multitasking, text-based, non-graphical, DOS compatible RTOS, coded for x86 platforms. Supports realtime use, embedded devices.
• Technosoftware, Inc. - RTXDOS-16 (DOS compatible) and RTXDOS-32 (WIN32 compatible) real-time OSs for embedded PCs. Modular systems with TCP/IP, WEB server, Process IO, OPC Toolkit, and IEC1131.