DR-DOS
operating system
DR-DOS is a disk operating system for IBM PC compatibles, originally developed by Gary A. Kildall's Digital Research and derived from Concurrent PC DOS 6.0, which was an advanced successor of CP/M-86. Upon its introduction in 1988, it was the first operating system that attempted to be compatible with IBM PC DOS and MS-DOS.
The first release was version 3.31, named to match MS-DOS's then-current version. DR DOS 5.0 was released in 1990 as the first to be sold in retail; it was critically acclaimed and led to DR DOS becoming the main rival to Microsoft's MS-DOS, who quickly responded with its own MS-DOS 5.0 but releasing over a year later. It introduced a graphical user interface layer called ViewMAX. DR DOS 6.0 was released in 1991; then with Novell's acquisition of Digital Research, the following version was named Novell DOS 7.0 in 1994. After another sale, to Caldera, updated versions were released partly open-source under the Caldera moniker, and briefly as OpenDOS. The previously last version for desktops, Caldera DR-DOS 7.03, was released in 1999, after which the software was sold to Embedded Systems by Caldera and then by DeviceLogics. In January 2022, Whitehorn Ltd. Co. registered the DR DOS trademark. Since 2026 it has been releasing beta versions of DR DOS 9.0, an operating system written from scratch and not based on the code of previous versions.
History
Origins in CP/M
Digital Research's original CP/M for the 8-bit Intel 8080- and Z80-based systems spawned numerous spin-off versions, most notably CP/M-86 for the Intel 8086/8088 family of processors.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Jul 18, 2026. The linked authority identifier is Q1046873. VIAF identifies the subject as 173853686. 1 of 2 selected statements include explicit references; 1 carry qualifiers and 0 use preferred rank. The first chronological checks are 1988, 1990, 1991 and 1994.
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This entry incorporates text from “DR-DOS” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.