In this post, 8bitMicroGuy offered to release his video games under a permissive license with the added condition that no derivative works contain "porn" or "blasphemy".
As others pointed out, this would be incompatible with all licenses that conform to the Debian Free Software Guidelines or the nearly identical Open Source Definition. In particular, a ban on "blasphemy" would violate section 5's non-discrimination guarantee. Thus it would conflict with reciprocal licenses that require all derivative works to be free, such as "copyleft" licenses for computer programs and "ShareAlike" licenses for cultural works. Furthermore, "porn" and "blasphemy" would be hard to even define in such a way that licensees can understand their rights.In [url=http://forums.nesdev.com/viewtopic.php?p=187041#p187041]this post[/url], 8bitMicroGuy wrote:I wouldn't like any strong language, obscene blood/gore, blasphemy or Satanic elements. The reason of this discrimination is that I want all Google searches, when a kid fan of my assets searches, show clean family-friendly and Christian-friendly content. I'm sick and tired of the impurity of everything, starting from the anthropomorphic fandom. Kids deserve a clean environment for anthropomorphic self-expression like I did when I was young.
The so-called rule 34 of the Internet asserts the existence of fan-made porn of every notable subject. Some brand owners claim harm from the presence of sexually explicit results in web searches for their brands, especially searches performed by children for brands marketed to children. The porn ban clause is intended to reserve an author's right to assert legal claims against those who produce or distribute porn related to a work's scenario and characters. But is it "indecent" to show a man's bare knees? It is to Muslims, who believe a man must be covered at least from navel through knees. This makes Nintendo's Punch-Out!! indecent. For a more recent homebrew example, the Mojon Twins' Cheril the Goddess has been called questionable.
Established religions also differ in their beliefs. For two and a half years, I studied the Bible with a Christian denomination that taught that YHWH the Father and Jesus the Son are separate persons, with Jesus the first created being, mighty but not Almighty, and the Holy Spirit not a person but the mechanism through which the Father interacts with the physical world. It also taught day-age theory, that the "days" in Genesis 1 are metaphorical, with durations thousands to billions of years long. And to them, the human soul is unconscious in the grave and completely destroyed in the lake of fire, not subject to eternal conscious torment. Is that "blasphemy"? Another denomination teaches that Jesus's surrogate mother Mary is the "queen of heaven", encouraging believers to pray for her intercession, and that an alcoholic beverage actually becomes Jesus's blood rather than representing it.
An incompatibility between a copyleft license on the engine and a morality-preserving license on the assets was perceived. This can be solved in a way that parallels how the Doom engine is separated from the WAD files that it displays. If the engine is under a free software license, and the assets are under a (technically non-free) morality-preserving license, a linker script can specify separate memory areas for the engine and assets to make them an aggregate. If there is asset-specific code, such as enemy behaviors, the author of a copylefted engine can grant an exception to link asset-specific code to engine code through a controlled interface. But elements under a ShareAlike license, which requires all derivatives to be free cultural works, would still need to be kept separate from elements under a morality-preserving license. Something like a crossover fighting game still couldn't combine the two.