DOS—a term now almost synomous with Microsoft (MS) and the PC. Before Windows, there was DOS. Before the Macintosh, Amiga, etc., there was DOS. And today, there is DOS (of course, UNIX is older than all of them ... and still going strong).
However, the history—as well as the current situation and future—of DOS is more complex than just "Microsoft." The first misconception is that Microsoft created DOS. The second is that there was only one DOS—MS-DOS. And third, it is believed that DOS's days are done.
The story of DOS is not really that of Bill Gates—it is the story of Gary Kildall, the maker of the original CP/M (Control Program for Microcomputers) operating system, and the founder of Digital Research (DR). CP/M, an 8-bit operating system written in 1974, is the foundation upon which all further DOSes (MS-DOS, PC-DOS, DR-DOS, etc.) are based.
In 1980 IBM decided to enter the still new "personal computer" market, and instead of "wasting" company resources, went "shopping" for a 16-bit operating system, courting both Kidall's Digital Research and Bill Gates' Microsoft. There are numerous rumors about why Kidall and DR did not get the nod; some argue Kidall was not cooperative, others say CP/M was still only 8-bit and DR wasn't willing to port quickly enough. Still others go for a type of conspiracy theory. The conspiracy theory may not hold water, but it is true that Bill Gates' mother had connections in high places, and many believe that his parents' wealth and connections are what got Microsoft its cozy space in bed beside IBM (remember, he is William Gates III). In any case, Microsoft got the contract, even though they did not at the time have an operating system to offer IBM—after all, Microsoft was basically a computer language company, not a supplier of system software. To remedy this problem, Bill and Co. licenced QDOS (Quick and Dirty DOS)—a 16-bit clone of the 8-bit CP/M, completed in 2 months—from a Seattle company, renaming it MS-DOS.
By version 2.0 MS-DOS had become the industry standard. However, the original plans for the IBM PC included offering several operating systems: MS-DOS (also PC-DOS; IBM and MS both ended up with ownership of the code and name. Until the less-than-friendly "divorce" of the two in the late 80s, there was one DOS with two names ... thereafter, two DOSes with two names ...), a 16-bit port of CP/M, and a Pascal-based operating system.
For much of the early 80s CP/M remained a popular platform, having hundreds of applications (more than most competing platforms, in fact); indeed, a co-processor expansion card was available for the Apple //e so that it could run CP/M (and DOS) applicatios. Eventually, DR created what became known as Digital Research DOS, or simply "DR-DOS." DR-DOS was not a clone of MS-DOS per se; it was a true, 100% compatible DOS, with its own implementations of the MS-DOS functions. When Windows eventually came out, DR-DOS could run it just as well as MS-DOS could.
DOS was a 16-bit, real-mode OS, had no pre-emptive multi-tasking, no protected memory, and seemed like a "dead-end." In fact, as early as 1983/84 IBM and MS had agreed to develop the successor to DOS—Operating System 2, or OS/2. However, throughout the decade, MS and DR research released newer and better releases of DOS. For a short period of time there was a multi-tasking version of DOS 4.0 in Europe (so I've read), but it was quickly pulled. In addition, DR's product line also expanded, including such DOS-children as DR Multiuser DOS, DR Concurrent PC-DOS, DR Concurrent Multiuser DOS, DR FlexOS, DR Net, etc., as well as the graphical shell GEM (Graphical Environment Manager).
By 1983 MS had proposed Windows to IBM, which turned them down—several times. However, several releases and overhauls later, MS Windows 3.x, combined with DOS, became a standard fixture on new PCs. With Windows 95, DOS did not disappear, but became more well-hidden. Windows 98 carried on the DOS legacy. The results of this are two-fold: 1) because MS-DOS is 16-bit, Windows 95 and 98 contain 16-bit code, reducing performance and stability, and 2) DR-DOS (try version 7.0) can be used "underneath" Windows 95. This latter fact is something MS has denied for years (and continues to deny, eventhough many users have successfully "separated" Windows from DOS, and have used DR-DOS to boot Windows 95, but that is neither here nor there...for now).
After the IBM/MS split, the two corporations continued to release their own versions of DOS. In 1995, IBM, for example, released PC-DOS 7.0. It has numerous advantages over MS-DOS 6.x. It seems that IBM has ceased active work on DOS as a modern platform, though copies of PC-DOS can be seen on storeshelves from time to time. There are also several other DOS versions out there—from the free to the expensive. Some of the commercial versions are meant primarily for business customers and enhance DOS's original features, whereas one free version is merely trying to serve as a replacement for MS-DOS. One of the "new" markets for DOS is in embedded systems; DOS can be placed on a ROM chip, and be used to operate any number of small devices.
But what of DR-DOS? The DR is in—DR's products were sold to Novell, which, as they did with UNIX, failed to do anything productive with them. They released several versions of Novell DOS, but that was about it, before selling these DR assets to Caldera, which released what was first OpenDOS 7.x or, and the DR-DOS 7.x (the "DR" was returned to more accurately indicate the "DR-DOS" heritage ...). In its new incarnation, DR-DOS is a 32-bit, pre-emptive multi-tasking OS which beats the hell out of any DOS that MS ever released. Furthermore, Caldera, by inheriting DR's assets from Novell, received the go-ahead with a lawsuit against MS for essentially keeping DR-DOS off computers through anti-competitive practices. Caldera entually spun off their DOS product line, and as of 2003 the DR-DOS assets are own by "Devicelogics," which plans a DR-DOS 8.0 release.
Hey...if you're using an old version of Windows, you're already using it!
But seriously: many old games run under DOS (though there are few new DOS games released). Many users, myself included, like the speed and power of a CLI (Command Line Interface). Even though DOS's CLI is a shoddy imitation of the Unix CLI, it still has enough power for most users. Plus, without the overhead of all the Windows APIs, etc., DOS can run quickly, especially on older systems.
If you have an old system—such as a 286, DOS is just about the only thing you can run on it. Plus, DOS was a very productive software platform: there are many old applications for DOS, including games, word processors, and even to graphical web-browsers.
Commercially, DOS may have a productive, if not extensive, life ahead of it in the embedded systems market. Using an emulator, such as DOSEMU or DOSBox, it is possible to run many old DOS programs (e.g. under Linux).
As boot (issue 15) stated: "It's DOS for god's sake. Some things are better left dead."
MS-DOS is clearly not a good option for anyone anymore. It is a 16-bit OS in a world of 32-bit machines, and the world looks to become 64-bit within a few years. Windows 98/ME was the last of Microsoft's DOS-based OSes.
In fact, MS-DOS was never the best option among the various DOSes ... just the default one. MS-DOS still has the infamous 640K barrier, and many things in DOS are poorly implemented.
Plus, there won't be many new applications for DOS in the future, and since the actual purpose of an OS is to serve as a buffer between software and hardware, taking care of basic tasks, if you don't have applications to run on an OS (or if you aren't hacking your system, learning about it), why use that OS?
Furthermore, many users balk at the idea of editing AUTOEXEC.BAT and CONFIG.SYS files—they simply want to be end-users. I know many people like this: they want to use their computer as a tool, not as a toy. Given the alternatives, DOS may not be the best option for these people.
DOS isn't dead ... people across the world still use it, and given all the older hardware that runs just dandy with DOS, I expect DOS to be around for quite a while.
If you've got an old 286 or 386—pull it out of the closet. Install DR-DOS. With the Web-Spyder web-browser (fully graphical, HTML 3.2 compatible), your old machine can be used to surf the Internet, write e-mail, etc.—your own network computer in the making.
Below you will find some links to other DOS-related sites. (Sorry, but Microsoft doesn't have any useful DOS information at their site)