Copyleft (also share-alike) is a concept of sharing something on the condition that others will share it under the same terms; this is practically always used by a subset of [free (as in freedom) software](free_software.md) and [culture](free_culture.md) to legally ensure this software/art and its modifications will always remain free. This kind of [hacks](hacking.md) [copyright](copyright.md) to de-facto remove copyright by its own power.
Copyleft has been by its mechanisms likened to a virus because once it is applied to certain software, it "infects" it and will force its conditions on any [descendants](fork.md) of that software, i.e. it will spread itself (in this case the word virus does not bear a negative connotation, at least to some, they see it as a good virus).
For free/open-source software the alternative to copyleft is so called **permissive** licensing which (same as with copyleft) grants all the necessary freedom rights, but does NOT require modified versions to grant these rights as well. This allows free software being forked and developed into [proprietary](proprietary.md) software and is what copyleft proponents criticize. However, both copyleft and permissive licensing are free as in freedom.
In the [FOSS](foss.md) world there is a huge battle between the copyleft camp and permissive camp ([LRS](lrs.md) advocates permissive licenses with a preference for 100% [public domain](public_domain.md)).
In the great debate of copyleft vs permissive free licenses we, as technological anarchists, stand on the permissive side. Here are some reasons for why we reject copyleft:
- By adopting copyleft one is **embracing and supporting the copyright laws and perpetuating the [capitalist](capitalism.md) ways** ("marrying the lawyers") because copyleft relies on and uses copyright laws to function; to enforce copyleft (prevent "disallowed" use) one has to make a legal action (while with permissive license we simply basically give up the rights to make a legal action). Copyleft chooses to play along with the capitalist bullshit [intellectual property](intellectual_property.md) game and threatens to [fight](fight_culture.md) and use force and bullying in order to enforce *correct* usage of information.
- In a way it is **[bloat](bloat.md)**. Copyleft introduces **legal complexity**, [friction](friction.md) and takes programmers' [head space](head_space.md) (every programmer has to study a bit of copyright law nowadays due to such BS), especially considering that copyleft is also probably largely ineffective as **detecting its violation and actual legal enforcement is difficult, expensive and without a guaranteed positive outcome** ([FSF](fsf.md) encourages programmers to hand over their copyright to them so they can defend their programs which just confirms existence and relevance of this issue). The effort spent on dealing with this is a wasted human time. Sure, corporations can probably "abuse" permissive (non-copyleft) software easier, but we argue that this is a problem whose roots lie in the broken basic principles of our society ([capitalism](capitalism.md)) and so the issue should be addressed by improving our socioeconomic system rather than by bullshit legal techniques that just imperfectly and many times completely ineffectively try to cure the symptoms while strengthening the system's mechanisms.
- **The scope of copyleft is highly debatable, introducing doubt/uncertainty** (which is why we have different kind of copyleft such as *strong*, *weak*, *network* etc.). I.e. it can't be objectively said what exactly should classify as violation of copyleft AND increasing copyleft scope leads to copylefted software being practically unusable. You may say "so what", but in law clarity is extremely important, it may also discourage people because they don't really know what they sign up for, commercial use may also be discouraged by this for the same reason which may have a similar effect to a non-free license that downright disallows commercial use. Consider this **example**: [Linux](linux.md) is copylefted which means we can't create a proprietary version of Linux, nevertheless we can create a proprietary operating system of which Linux is part (e.g. [Android](android.md) in which its proprietary app store makes it de-facto owned by [Google](google.md)), and so Linux is effectively used as a part of proprietary software -- the copyleft is bypassed. One might try to increase the copyleft scope here by saying *"everything Linux ever touches has to be free software"* which would however render Linux unusable on practically any computer as most computers contain at least some small proprietary software and hardware. The restriction would be too great.
- **Copyleft licenses have to be complex and ugly** because they have to strictly describe the copyleft scope and include lots of legal [boilerplate](boilerplate.md) in order to make them well defendable in court (copyleft is really about preparing for a legal war) -- and as we know, complexity comes with bugs, vulnerabilities, it makes it incomprehensible to common people and imposes many additional burdens. Indeed, we see this in practice: the only practically used copyleft licenses are the various versions of GPL of which all are ugly and have historically shown many faults (which is again evident from e.g. looking at GPL v1 vs v2 vs v3). This introduces great license compatibility issues, headaches for programmers who should rather be spending time programming and other similar bullshit. Permissive licenses on the other hand are simple, clear and well understandable, they aren't as much preparing for a court battle as trying to give other hackers a peace of mind and make them free of legal worries.
- **Copyleft prevents not only inclusion in proprietary software but also in permissive FREE software.** I.e. as a consequence of denying code to corporations collateral damage is done by also denying code to ethical free software that wishes to be distributed without copyleft conditions. Similarly to how proprietary software forces free software programmers to reinvent wheels by rewriting software as free, copyleft forces permissive free software programmers to reinvent wheels and rewrite copylefted code as permissive. In this way copyleft [fights](fight_culture.md) not only proprietary software, but also other kinds of free software.