The Redmond software giant is making its Windows installer technology under OSI's Common Public License.
On Monday, Microsoft released some of its code under an open-source license, and posted it on SourceForge, the open-source code repository.
To date, Microsoft has made its source code available under a variety of licensing mechanisms, all under its "shared source" umbrella. But until today, the company had not released code under what is commonly considered a true open-source license.
Microsoft made available an internally-developed product called the "Windows Installer XML" (WiX) to SourceForge. The code is downloadable here.
WiX is a toolset for building Windows installation packages from XML source code. It runs on Windows NT and Windows 2000.
"We've been learning from open source about the importance of sharing code with developers," said Jason Matusow, manager of Microsoft's shared source initiative. "We know it's important to have a full-spectrum approach" to licensing software under shared source, he added.
"Each product team across Microsoft needs to do what makes sense," said Matusow. Some are holding source code close to the vest. Others are issuing it under modified BSD licenses. In other cases, teams are releasing it under customized licenses, as with Windows CE Premium, he explained.
A number of Microsoft teams from across the company — including the Yukon database, Office 12, Exchange "Kodiak," Update Services and Xbox divisions — have employed WiX in building their products, Matusow noted.
Word that Microsoft might be preparing to release some of its "non-core" code via an open-source licensing mechanism first leaked last week.
The decision to release WiX on SourceForge isn't as far-fetched as it might seem, Matusow claimed.
More than 25 percent of current SourceForge projects are Windows-related, Matusow said. Because WiX isn't a .Net project, per se, Microsoft decided against releasing the WiX code on its own SourceForge alternative, called GotDotNet Workspaces. Read More About GotDotNet Workspaces Here
And Microsoft plans to label its WiX CPL program as one of its "shared source" options, Matusow reiterated. See Microsoft\'s List of Shared Source Licensing Options Here
The Common Public License (CPL) was developed by IBM and is an evolution of the IBM Public License (IPL). The CPL was approved by the Open Source Initiative (OSI) in May 2001. The Eclipse open-source development-tool framework is licensed under CPL.
Matusow said that the CPL licensing terms are ideal for WiX. Any size or type of customer can download the code (even though WiX is most useful for teams of 10 developers or more, according to Matusow). CPL bestows commercial rights for modification and distribution. It insures patentability (on a royalty-free basis). It allows individuals to build on top of the technology and use the resulting products commercially and/or proprietarily. And all changes made to the source must be returned to the community, even though the individual(s) who make the changes retain ownership rights to them. Microsoft Watch