The Free Software Foundation published a clarifying blog post this weekstating that the organization is “happy when people use GNU licenses to distribute and license software.”
But “we condemn the use of unauthorized and confusing derivatives of the licenses.”
Unfortunately, some authors engage in confusing practices by writing licenses using the existing terms and conditions of the GNU Free Software Licenses, without intending to grant the four freedoms to users. For example, we have long seen attempts to add restrictions to the license text itself, placed in the LICENSE file or included elsewhere in the program release. An example is the so-called “Common property clause“, which, when applied to a free software license, asserts that the program is covered by the license. But, at the same time, is contradictory in its meaning by asserting that the sale of copies of the program or the implementation of a commercial service with the program is prohibited.
The immediate consequence of this practice of inserting a restriction into a GNU license in this way is the confusion it causes for the community. Users still see the original license name, with its preamble and terms and conditions intact, conveying a strong message that the purpose of the license is to allow users: to agree users — their essential software freedoms. This message is clear from the license text and is reinforced by the reputation acquired by the FSF and GNU brands, as well as their decades of advocacy for free software. At the same time, these same users see a contradictory statement of the “Commons Clause”, which is clearly contrary to the spirit of the free software movement and the definition of free software…
(P)To make it even clearer that the additional restrictions are inconsistent with our license, we have given users the right to remove these added restrictions (in 2007) and preserve the freedom of the program. But we at the FSF have another legal tool against attempts to release programs under GNU General Public Licenses that have been wrongly modified to become non-free licenses. The FSF holds common law copyrights and trademarks to the GNU family of General Public Licenses. Additionally, the FSF holds registered trademarks for “FSF”, “Free Software Foundation” and “GNU”. (…) We cannot control the drafting of proprietary software licenses by others, but we can and do prohibit doing so in a manner that misleadingly associates such licenses with GNU or the GNU Licenses. .(We) have the right to legally enforce our copyright and trademark for FSF licenses that have been modified by additional restrictions to a textual GNU license…
Licenses that confuse users about the freedoms they grant are detrimental to the free software movement because they threaten to dilute the value and power of those licenses. When GNU licenses are misused through such confusing practices, it harms the reputation earned by the GNU Project and the FSF over decades of free software advocacy. It is our duty to all computer users to stop these practices and, if necessary, we will use our legal rights to do so.
