Samba developers have slammed the open source licencing deal reached earlier this month, calling it "unacceptable" and warning of significant damage to the open source community.

The deal has attracted criticism from open-source advocates, and Samba's open letter to Novell argues that the agreement goes against the goals of open source, or free software, and shows contempt for open source developers.

"For Novell to make this deal shows a profound disregard for the relationship that they have with the Free Software community," Samba developers wrote. Proprietary software, unlike open source, forces users to sign coercive licensing agreements, dividing the world between those who have licenses and those who don't, the developers wrote. The deal between Microsoft and Novell, they said, will have a similar effect.

"It deals with users and creators of free software differently depending on their 'commercial' versus 'non-commercial' status, and deals with them differently depending on whether they obtained their free software directly from Novell or from someone else," the letter stated. "The goals of the Free Software community and the GNU GPL allow for no such distinctions." The Linux kernel and components such as Samba are distributed under the GNU General Public License.

The deal also weakens the open source community's defenses against software patent litigation, Samba developers wrote. "Only by standing together do we stand a chance of defending against the peril represented by software patents. With this agreement Novell is attempting to destroy that unified defense, exchanging the long term interests of the entire Free Software community for a short-term advantage for Novell over their competitors." The letter called on Novell to work with the Software Freedom Law Center to undo the agreement.

In the deal, Microsoft agreed to offer support for Novell's SuSE Linux, and agreed not to assert rights over patents to any software technology that might be incorporated into the distribution.

Novell has said the deal complies with the GPL. To help answer the flood of questions around the agreement the company published a question-and-answer page on its website.