I used to prefer permissive licenses and now favor copyleft
Within free open source software (and free content more generally), there are two major categories of copyright licenses: permissive licenses freely share with everyone, and copyleft licenses freely share only with those who are also willing to freely share. I have been a fan of, and developer of, free open source software and free content ever since I've been old enough to understand what these things are and build things that I thought other people might find useful.
Historically, I was a fan of the permissive approach (eg. my blog is under the WTFPL). More recently, I am warming up to the copyleft approach. This post explains my reasons why.
Why I was historically a fan of permissive licenses
The first reason for my preference of permissive licenses over copyleft licenses was to maximize adoption and distribution of my work. By releasing it under permissive licenses, I made it clear that there was nothing anyone needed to worry about if they wanted to build off of something I make. Enterprises are often unwilling to release their projects freely, and given that I did not see myself having any ability to nudge them to fully join the free software side, I wanted to avoid being needlessly incompatible with the approach they already had and would not give up.
The second reason for my preference of permissive licenses over copyleft licenses was philosophical. I generally philosophically dislike copyright (and patents). I dislike the idea that two people privately sharing bits of data between each other can be perceived as committing a crime against a third party whom they are not touching or even communicating with and are not taking anything away from.
Explicitly releasing to public domain is legally complicated for various reasons, and so a permissive license is the cleanest and safest way to get as close as possible to not copyrighting your works. I do appreciate the copyleft idea of "using copyright against itself" - it's a beautiful legal hack.
In some ways it's similar what I always found philosophically beautiful about libertarianism. As a political philosophy, it's often described as banishing the use of violent force except for one application: to protect people from other violent force. As a social philosophy, I sometimes see it as a way of taming the harmful effects of the human disgust reflex by making freedom itself a sacred thing that we find it disgusting to defile.
However, while copyleft of written work fits into this definition, GPL-style copyright of code oversteps beyond a minimalistic notion of "using copyright against itself", because it offensively uses copyright for a different purpose: mandating publication of source code. This is a public-spirited purpose, and not a selfish purpose of collecting licensing fees, but it is nevertheless an offensive use of copyright.
Why I am warmer to copyleft today
The switch from favoring permissive to favoring copyleft is motivated by two world events and one philosophical shift. First, open source has become mainstream, and nudging enterprises toward it is much more practical.
Pleantly of companies in all kinds of industries are embracing open source. Companies like Google, Microsoft and Huawei are embracing open source, and even building major software packages open. New industries, including AI and of course crypto, are heavier on open source than previous industries ever were.
Second, the crypto space in particular has become more competitive and mercenary, and we are less able than before to count on people open-sourcing their work purely out of niceness. Hence, the argument for open source cannot just rely on "please"; it must also be accompanied by the "hard power" of giving access to some code only to those who open up theirs.
Incentivizing open source is most valuable in situations where it's neither unrealistic, nor guaranteed. Today, both mainstream enterprise and crypto are in that situation. This makes the value of incentivizing open source via copyleft high.
Economic arguments for copyleft
Glen Weyl-style economic arguments have convinced me that, in the presence of superlinear returns to scale, the optimal policy is actually NOT Rothbard/Mises-style strict property rights. Rather, the optimal policy does involve some nonzero amount of more actively pushing projects to be more open than they otherwise would be.
Fundamentally, if you assume economies of scale, then by simple mathematical reasoning, nonzero openness is the only way that the world does not eventually converge to one actor controlling everything. Economies of scale means that if I have 2x the resources that you do, I will be able to make more than 2x the progress.
Hence, next year, I will have eg. 2.02x the resources that you do. Hence... Left: proportional growth. Small differences at the start become small differences at the end. Right: growth with economies of scale. Small differences at the start become very large differences over time.
Threats to balanced growth
A key pressure that has prevented this dynamic from getting out of hand historically is the fact that we are not able to opt out of diffusion of progress. People move between companies and between countries and take their ideas and talents with them. Poorer countries are able to trade with richer countries and get catch-up growth.
However, several trends threaten this balance, and at the same time threaten other factors that have kept unbalanced growth in check:
- Increased consolidation of companies
- The rise of large tech companies
- Patent trolls
- Regulatory capture
This all increases the possibility of persistent, and even self-reinforcing and growing, power imbalances between companies and between countries. For this reason, I am increasingly okay with stronger efforts to make diffusion of progress something that is more actively incentivized or mandatory.
Copyleft as a solution
Some recent policies made by governments can be interpreted as being about attempting to actively mandate higher levels of diffusion: In my view, the downsides of policies like these tend to come from their nature of being coercive policies of a government, which leads to them preferentially incentivizing types of diffusion that are heavily tilted toward local political and business interests.
But the upside of policies like this is that they, well, incentivize higher levels of diffusion. Copyleft creates a large pool of code (or other creative products) that you can only legally use if you are willing to share the source code of anything you build on it.
Hence, copyleft can be viewed as a very broad-based and neutral way of incentivizing more diffusion, getting the benefits of policies like the above without many of their downsides. This is because copyleft does not favor specific actors and does not create roles for active parameter setting by central planners.
Conclusion
The benefits of copyleft are much greater today than they were 15 years ago, and projects that would have gone permissive 15 years ago should at least think about adopting copyleft today. In the future, maybe we can have open-source cars. And perhaps copyleft hardware can help make that happen.