Open source, for me, is the very practical "proof" for the claim that "as soon as their [humans] interests do not absolutely clash, act in concert, harmoniously, and perform collective work of a very complex nature". That is to say that humans can act together as a group without a central authority (like your boss, the state, your mom) telling them what to do and how. (More on this topic in this mastodon thread of mine)
It is also, as Holloway puts it, a crack: "We shall not labour under the command of capital, we shall do what we consider necessary or desirable".
Groups of random people come together (online or offline) to work on massive projects such as Linux, Git and tons of other tools that we use on a daily basis - without profit incentive or a central authority to manage everything. Yes we have guidelines, coding styles etc., yes we have code reviews, pipelines and quality assurances. But we build those ourselves (in most cases).
The absence of an authority does not mean the absence of order. We can come to a consensus on what we need to keep our code clean and maintainable. We do not need a Company or boss telling us to do so.
"It is a testament to the power of communities coming together to innovate and provide accessible solutions for all." to quote Will Ruddick.
While Kropotkin's example of complex work included creating lifeboats, railways and the red cross, I'd like to bring software engineering as the next example. A complex endeavour it is.
While coding, scripting and "hacking" something quick together may not be that complex (a couple ifs, a couple fors), creating a operating system kernel is a whole other operation. But we have one of the biggest and most used operating system, thanks to open source collaboration (most used, but maybe not on desktop).
The complexity of open source projects knows no bounds: We have Game Engines, Games, Operating Systems and tools for those (like webservers, editors and more), and even whole systems to create and maintain IaC projects.
Most FOSS project start out without a profit incentive. Linux was started as a hobby project ("I’m doing a (free) operating system (just a hobby, won’t be big and professional like gnu) for 386(486) AT clones." - Linus Torvalds). Osu!, a rhythm game is open source as well, which has led to a more collaborative and sustainable approach to the games development. OpenTofu was created in spite of Terraform becoming closed-source.
These examples (and a lot more) show the stance of "not labour[ing] under capital", but instead do what we desire - or what is necessary.
Wherever capital creeps in and fucks up, open source comes to the rescue. Don't like that the new copilot spies on you 24/7 while using your machine? Switch to Linux. Licensing of Terraform may become tedious and expensive? Switch to OpenTofu. Unity charges you per download? There's Godot. Don't want AI chatbots to steal all your data? Here's ollama and open models.
Most (if not all) of these project start without a profit incentive, and because we want to do them and/or need them. Some are better than others (looking at you LibreOffice), some may have a grotesque GUI, some may not even have an GUI. But they're here because we need them. But I see this as a big downside: Developers build projects for developers - we need to collaborate with other creatives as people as well. We have to make our software usable for the everyday joe. But we may not have the funds, capacity, know how or people to do so (yet).
Whenever there is a "crack", a movement of emancipation, a movement of liberation from capital, Capital likes to strike back. This can take many different forms: (Violent) attacks against the "crack", gaslighting, fear-mongering and - if all else fails - co-opting the "crack".
We can see this very good during PRIDE month. Rainbow capitalism is popping left and right. What happened to the goals of queer theory and queer liberation? We don't care, we want to sell rainbow coloured stuff you, while funding trans- and/or homophobic organisations.
We can see this with "feminism". "Gaslight, Gatekeep, Girlboss". Let's give women the right to vote and the ability to take on jobs. Let's make them "equal", but only on paper (if even). Why do we need a feminist strike? You already have all the same rights (ok, maybe we're back to the gaslighting phase with this one).
Whenever there is a "crack" to current hierarchies, capitalist co-opt them and makes them ready to consume. And the same is happening to open source. Companies like Microsoft are jumping on the "FOSS" train, only to then leave once they drained the community for free "labour".
We've seen it with HashiCorp, Oracle and more. (Remember MySQL and MariaDB; or openOffice)
Who's to say that other companies like Microsoft wont follow suit and "rug-pull" our codebases from us.
It's time to take back control over our code, tools and software: Support FOSS projects with Code contributions, legal help, design work (both in terms of UI/UX/GUI and software design) and/or a financial donation to your favourite open-source projects that may be massively underfunded.