'''RTMOS (Real-Time Multiprogramming Operating System)''' was ana [[process control]] [[operating system]] developed in the 1960s by [[General Electric]]<ref>{{cite book|url=http://bitsavers.informatik.uni-stuttgart.de/pdf/ge/PAC-4000/GET-3471_PAC-4020_PgmgMan_Oct67.pdf|title=GE-PAC 4020 Programming Manual|page=5|year=1967|format=PDF|publisher=[[General Electric]]|accessdate=2013-09-27}}</ref> that supportssupported both [[real-time computing]] and [[multiprogramming]].<ref name=Spang1972>{{cite journal|last=Spang|first=H. A. III|title=The structure and comparison of three real-time operating systems for process control|journal=Automatica (Journal of IFAC)|date=1972|month=January|volume=8|issue=1|pages=49-64|doi=10.1016/0005-1098(72)90009-X|url=http://dl.acm.org/citation.cfm?id=2244947|accessdate=23 August 2013}}</ref><ref name="Spang 1974">{{cite journal|last=Spang|first=H. A. III|title=Measurement and Improvement of Memory Allocation in a Process Computer|journal=4th IFAC/IFIP International Conference on Digital Computer Applications to Process Control|year=1974|volume=93|pages=236-247|doi=10.1007/978-3-642-65796-2_20|url=http://link.springer.com/chapter/10.1007%2F978-3-642-65796-2_20|accessdate=23 August 2013}}</ref> Multiprogramming operating systems are now considered obsolete, having been replaced by [[computer multitasking|multitasking]].
