While applauding Microsoft's contribution of code to the Linux community this week, Red Hat nonetheless urged its rival to pledge that it will never use its patents against Linux.
In a write-up by the Red Hat legal team on Tuesday, Red Hat emphasised Microsoft's change in behaviour, in which Microsoft offered up 20,000 lines of code for Linux drivers linking Linux to Microsoft virtualisation software.
"Microsoft has offered a significant contribution to the Linux kernel under the GNU General Public License version 2. This is important news," the legal team said. "It seems like only yesterday that Microsoft was declaring Linux, open source software, and the GPL to be the axis of evil. Now Microsoft is making a credible opening bid to become a member of the Linux community. As the largest corporate contributor to the Linux kernel, Red Hat would like to acknowledge this and encourage Microsoft to continue on this path."
But Microsoft needs to go a step further and promise to not use any patents against Linux, Red Hat's legal team said.
"Patent threats are irreconcilable with the norms and values that are at the heart of Linux. To win the respect and trust of the Linux community, Microsoft should unequivocally disavow such conduct and pledge that its patents will never be used against Linux or other open source developers and users.
Microsoft in the past has claimed Linux and open source software violated 235 patents and that users of open source software owed royalties to Microsoft.
A Microsoft official responded on Wednesday that there is a balance between contributing to open source projects and insistence on respect for intellectual property.
"Some observers question how a company can contribute to open source projects while, at the same time, insisting on respect of its intellectual property rights by its competitors," said Horacio Gutierrez, Microsoft corporate vice president and deputy general counsel, in a Microsoft blog entry. "In fact, these two things are not inconsistent, and striking a balance between them is one of the key things every commercial technology company must do in order to compete effectively in a mixed source world."
Microsoft on Tuesday made a further GPL contribution with the release of Microsoft Live Services Plug-in to integrate the company's Live@edu services with the Moodle course management system.