by Citrix References Further reading External links https://web.archive.org/web/20190401161050/http://www.imsltd.com/ former Intelligent Micro Software (IMS) website (vendors of IMS Multiuser DOS, IMS REAL/32, and REAL/NG) https://web.archive.org/web/20010515195706/http://www.lii.com/ former Logan Industries (LLI) website (IMS REAL/32 US distributor up to 2002-05-01) https://web.archive.org/web/20071213140207/http://www.conctrls.com/ former Concurrent Controls website (CCI Multiuser DOS) https://web.archive.org/web/*/https://applica.com Applica, Inc. website https://web.archive.org/web/20040412051935/http://www.aplycon.com/ former Aplycon Technologies, Inc. website CP/M variants Disk operating systems DOS variants Real-time operating systems Digital Research operating systems Novell operating systems Microcomputer software Discontinued operating systems Proprietary operating systems