Microsoft has released the source code for early versions of MS-DOS and Word for Windows, making them available to the public through the Computer History Museum.
The source codes on display will include MS-DOS 1.1, MS-DOS 2.0, and Microsoft Word for Windows 1.1a. All were developed and released in the 1980s.
The archaic MS-DOS operating system started as a request by IBM. Microsoft acquired the rights to 86-DOS from Seattle Computer Products, which would eventually become MS-DOS and PC-DOS, the latter being IBM's version.
To understand just how different computing was back then, and how far we've come, MS-DOS had less than 300KB of source code.
A little bit of history
"For more than a year, 35 of Microsoft's staff of 100 worked fulltime (and plenty of overtime) on the IBM project," Bill Gates, co-founder and former CEO of Microsoft, said in an interview in PC Magazine's first issue in the early 1980s.
"Bulky packages containing computer gear and other goodies were air-expressed almost daily between the Boca Raton [IBM] laboratory and Seattle [Microsoft]. An electronic message system was established and there was almost always someone flying the arduous 4,000 mile commute."
Microsoft Word for DOS was released in 1983, but Word for Windows didn't follow until 1989. It was this release that catapulted Microsoft to the head of the word-processing market, earning it half the revenue of the entire sector within four years.
These early pieces of history will be preserved at the Computer History Museum in Mountain View, California, where they will be available for scholars and members of the public to consult.
Microsoft still have the last version of MS-DOS available for download on Technet.