Over the years, Microsoft statements toward open-source software have ranged from derision and threats to mollification and even cautious praise.
is just the latest refinement of the company's ambivalence. At the same time that Microsoft's new arrangement opens up previously secret specifications and protocols for use in open-source software, it also insists that companies planning on distributing or using that software need a patent license.
So to put the news into historical context, here's a chronology of some of Microsoft's statements and practices regarding open-source software over the years:
On October 31, 1998, the first so-called "Halloween memo" from Microsoft suggested that some in the company saw open-source software as a major threat. "The intrinsic parallelism and free idea exchange in open-source software has benefits that are not replicable with our current licensing model and therefore present a long-term developer mindshare threat," the memo said, suggesting that one way to thwart open-source software would be to extend communication protocols with Microsoft-only changes.
In May 2001, Microsoft Senior Vice President Craig Mundie derided the business model of open-source software companies that aim to sell support rather than software licenses, likening the practice to that of failed dot-com companies. "A common trait of many of the companies that failed is that they gave away for free or at a loss the very thing they produced that was of greatest value--in the hope that somehow they'd make money selling something else," Mundie said.
In June 2001, Microsoft co-founder Bill Gates described the widely used General Public License as "Pac-Man-like," referring to the GPL's requirement that software tightly integrated with GPL components must by the license also be governed by the GPL.
In a June 2001 interview with the Chicago Sun-Times, Microsoft Chief Executive Steve Ballmer said, "Linux is a cancer that attaches itself in an intellectual property sense to everything it touches...The way the license is written (the Linux kernel uses the GPL), if you use any open-source software, you have to make the rest of your software open source."
A newer "Halloween" internal memo, based on research in 2001, warned that Microsoft's attacks on open-source software and licensing "are not effective" and are backfiring.
In an October 2002 interview, Ballmer touted Microsoft's shared-source program, which initially emulated some open-source attributes without giving programmers full freedoms. "We're learning...from the Linux world...If you take a look at the Linux world...There are many more communities in the Windows world than in the Linux world. I don't think we have mobilized that community as effectively as the Linux community has."
In June 2003, Pete Houston, Microsoft's senior director server strategy, said Microsoft had moved beyond its philosophical attacks and had begun trying to show customers the "business value" of Microsoft products. "I don't see the Linux community development model building the integrated offerings we have today," he said.
A Microsoft executive, Richard Emerson, helped to arrange an October 2003 investment of $50 million in The SCO Group shortly after it began a high-profile but largely unsuccessful attack that argued Linux violated the company's Unix intellectual property, according to the head of BayStar Capital, which made the investment.
In January 2004, Microsoft launched a "Get the Facts" ad campaign to try to show the cost advantages of Windows and other Microsoft products compared with open-source rivals.
Midway through the decade, Microsoft softened its attacks and even began launching its own open-source projects.
In June 2005, Ballmer said Microsoft isn't trying to compete with the philosophy behind Linux, only with it as a software product. "We come to work every day and we compete with products, we don't compete with movements," he said.
In June 2006, Microsoft launched a site called CodePlex to host shared-source projects.
In May 2007, Ballmer and Brad Smith, Microsoft's top lawyer, said Linux and other opens-source projects collectively violate 235 Microsoft patents. "We live in a world where we honor, and support the honoring of, intellectual property," Ballmer said in an interview with Fortune. Microsoft's open-source competitors must "play by the same rules as the rest of the business."
In September 2007, Clint Patterson, public relations director for Microsoft's Unified Communications Group, said: "The open-source development model has yet to demonstrate the ability to support profitable software businesses that can drive the coordinated research and testing necessary to sustain innovation."
In October 2007, after Red Hat Linux had declined to enter into a patent licensing-deal the way rival Novell had, Microsoft's Ballmer told an audience that customers using Red Hat Linux need to pay Microsoft for its intellectual property. "People (who) use Red Hat, at least with respect to our intellectual property, in a sense have an obligation to eventually to compensate us."
In October 2007, the, meaning that projects governed by those licenses may be called open-source software.
Finally, here's how Ballmer described Thursday's move: "Our goal is to promote greater interoperability, opportunity, and choice for customers and developers throughout the industry by making our products more open and by sharing even more information about our technologies."