Microsoft and open source

Microsoft, a tech company historically known for its opposition to the open source software paradigm, turned to embrace the approach in the 2010s.

From the 1970s through 2000s under CEOs Bill Gates and Steve Ballmer, Microsoft viewed the community creation and sharing of communal code, later to be known as free and open source software, as a threat to its business, and both executives spoke negatively against it.

Within a year of founding Microsoft, Bill Gates wrote an open letter that positioned the hobbyist act of copying software as a form of theft.

Internal strategy memos from this period, known as the Halloween documents, describe the company's potential approaches to stopping open source momentum.

[12] Bill Gates and Microsoft CEO Steve Ballmer suggested free software developers and the Linux kernel were communist.

[16] In 1998, Microsoft published at least one public beta release of their Services for UNIX (SFU)[17] based on the MKS toolkit, which in turn included some GNU utilities licensed under the GPL.

In June 2004, for the first time Microsoft was represented with a booth at LinuxTag, a free software exposition, held annually in Germany.

In August 2004, Microsoft made the complete source code of the Windows Template Library (WTL) available under the Common Public License and released it through SourceForge.

In the same year, Microsoft ported PHP to Windows under PHP License[16] and also partnered with and commissioned Vertigo Software to create Family.Show, a free and open-source genealogy program, as a reference application for Microsoft's latest UI technology and software deployment mechanism at the time, Windows Presentation Foundation and ClickOnce.

The initial agreement endured until 2012 and included promises not to sue over patents as well as joint development, marketing and support of Windows – Linux interoperability solutions.

The company also purchased 70,000 one-year SUSE Linux Enterprise Server maintenance and update subscription coupons from Novell.

[16] Also in 2008, Microsoft began distributing the open source jQuery JavaScript library together with the Visual Studio development environment for use within the ASP.NET AJAX and ASP.NET MVC frameworks.

[34] In November 2009, Microsoft released the source code of the .NET Micro Framework to the development community as free and open-source software under the Apache License 2.0.

[35] StyleCop, an originally proprietary static code analysis tool by Microsoft, was re-released as an open-source in April 2010 on CodePlex.

Based on customer feedback, Microsoft relicensed IronRuby, IronPython, and the Dynamic Language Runtime (DLR) under Apache License 2.0 in July 2010.

[39][40] In 2012, Microsoft began hosting Linux virtual machines in the Azure cloud computing service and CodePlex introduced git support.

Also, ASP.NET, ASP.NET MVC, ASP.NET Razor, ASP.NET Web API, Reactive extensions, and IL2JS (an IL to JavaScript compiler) were released under Apache License 2.0.

The company is dedicating engineering hours to help further develop libgit2 and working with GitHub and other community programmers who devote time to the software.

[16] In the beginning of 2015, Microsoft open sourced the Z3 Theorem Prover, a cross-platform satisfiability modulo theories (SMT) solver.

[53] In January 2016, Microsoft became Gold Sponsor of SCALE 14x – the fourteenth annual Southern California Linux Expo, a major convention.

[55] When Microsoft acquired Xamarin and LinkedIn in 2016, it relicensed the Mono framework under MIT License and continued maintaining the Kafka stream-processing software platform as open source.

In March 2016, Ballmer changed his stance on Linux, saying that he supports his successor Satya Nadella's open source commitments.

[16] In 2018, the Microsoft CTO of Data spoke with ZDNet about the growing importance of open source stating that: We meet customers where they are, and in particular if you want Linux we'll give you Linux; if you want MySQL, well we'll give you MySQL; you want NoSQL well we'll give you NoSQL -- that means you need to be part of open source; open source by nature is a community thing.Microsoft became Platinum Sponsor and delivered the keynote of the 2018 Southern California Linux Expo – the largest community-run open-source and free software conference in North America.

As part of its announcement, Microsoft acknowledged Linux's role in small devices where the full Windows operating system would be unnecessary.

In-keeping with the GPL open source license, Microsoft will submit its kernel improvements for accommodation into the master, public release.

[96] In 2020, Microsoft open sourced the Java extension for Microsoft SQL Server,[16] MsQuic (a Windows NT kernel library for the QUIC general-purpose transport layer network protocol),[97] Project Petridish, a neural architecture search algorithm for deep learning,[98] and the Fluid Framework for building distributed, real-time collaborative web applications.

[113][114] In February 2021, Microsoft made the source code for its Extensible Storage Engine (ESE) available on GitHub under MIT License.

[116][117] In March 2021, Microsoft became founding member of the new Eclipse Adoptium Working Group whose goal is to promote free, open source Java runtimes.

[120] In the following month, Microsoft launched an open source project to make the Berkeley Packet Filter work on Windows.

[123] Microsoft released the source code of 3D Movie Maker under the MIT License in May 2022,[124][125] following a request by the Twitter user Foone a month earlier.