Microsoft announced today that its partnering with the Computer History Museum to make the source code for early versions of MS-DOS and Word for Windows available to the public for the first time. Microsofts MS-DOS began when the company was approached by IBM to work on a project codenamed Chess. Microsoft originally provided a BASIC language interpreter to IBM, but then was asked to make an operating system. The company ended up making two versions, licensing PC-DOS to IBM, and reserving MS-DOS for other PC manufacturers. Word for Windows was released in 1989, and within four years it was generating half the worldwide word processing markets revenue.