Users with netbooks and consumer ultraportable laptops can now upgrade to Windows 7 using a free, open-source tool... released by Microsoft this week. No, you haven't slipped into a bizarro dimension where Richard Stallman and Steve Ballmer have switched places. Rather, as Ars Technica reports, Microsoft has made the tool's source public after facing heat for including some code released under the GPL without offering its derived work under the same license.
The tool is now available as a free download from this page on the Microsoft Store. When run, the program pops up a setup wizard asking for an ISO disk image of the Windows 7 installer, which is one of the ways Microsoft distributes its operating system on the Microsoft Store. Once the tool has done its thing, users should be left with a bootable USB drive that behaves just like a Windows 7 installation DVD.
Microsoft provides detailed instructions on the same page. The procedure looks to require a USB drive with at least 4GB of capacity, and Windows XP users will need to install the latest .NET framework and Microsoft's Image Mastering API, as well.
Developers, meanwhile, will find the source code in a zipped file on Microsoft's CodePlex website page. As Ars points out, the Windows 7 USB/DVD Download Tool is written in C#. Microsoft provides build instructions for Visual Studio 2008 in the included "read me" file.