“Interoperability” is the act of making a new product or service work with an existing product or service: modern civilization depends on the standards and practices that allow you to put any dish into a dishwasher or any USB charger into any car’s cigarette lighter.

But interoperability is just the ante. For a really competitive, innovative, dynamic marketplace, you need adversarial interoperability: that’s when you create a new product or service that plugs into the existing ones without the permission of the companies that make them. Think of third-party printer ink, alternative app stores, or independent repair shops that use compatible parts from rival manufacturers to fix your car or your phone or your tractor.

Adversarial interoperability was once the driver of tech’s dynamic marketplace, where the biggest firms could go from top of the heap to scrap metal in an eyeblink, where tiny startups could topple dominant companies before they even knew what hit them.

But the current crop of Big Tech companies has secured laws, regulations, and court decisions that have dramatically restricted adversarial interoperability. From the flurry of absurd software patents that the US Patent and Trademark Office granted in the dark years between the first software patents and the Alice decision to the growing use of "digital rights management" to create legal obligations to use the products you purchase in ways that benefit shareholders at your expense, Big Tech climbed the adversarial ladder and then pulled it up behind them.

That can and should change. As Big Tech grows ever more concentrated, restoring adversarial interoperability must be a piece of the solution to that concentration: making big companies smaller makes their mistakes less consequential, and it deprives them of the monopoly profits they rely on to lobby for rules that make competing with them even harder.

For months, we have written about the history, theory, and practice of adversarial interoperability. This page rounds up our writing on the subject in one convenient resource that you can send your friends, Members of Congress, teachers, investors, and bosses as we all struggle to figure out how to re-decentralize the Internet and spread decision-making power around to millions of individuals and firms, rather than the executives of a handful of tech giants.

• Interoperability: Fix the Internet, Not the Tech Companies: a taxonomy of different kinds of interoperability, from “indifferent interoperability” (I don't care if you plug your thing into my product) to “cooperative interoperability” (please plug your thing into my product) to “adversarial interoperability” (dang it, stop plugging your thing into my product!).
• Unix and Adversarial Interoperability: The ‘One Weird Antitrust Trick’ That Defined Computing How do you get a ruthless monopolist to sit on its hands while competitors large and small make interoperable versions of one of its inventions? The story of Unix shows the way.
• alt.interoperability.adversarial: The history of the alt. hierarchy shows how an Internet dominated by protocols, not products, ensured that users could shape their online experiences. Restoring legal protections to interoperators could turn today's Big Tech companies back into protocols that anyone could plug a new service into.
  
• Adversarial Interoperability: Reviving an Elegant Weapon From a More Civilized Age to Slay Today’s Monopolies: The history of adversarial interoperability and how it drove the tech revolutions of the past four decades, and what we can do to restore it.
• Gopher: When Adversarial Interoperability Burrowed Under the Gatekeepers' Fortresses: Before the Web devoured Gopher, Gopher devoured mainframes.
• Interoperability and Privacy: Squaring the Circle: Big Tech companies created a privacy dumpster fire on the Internet, but now they say they can’t fix it unless we use the law to ban competitors from plugging new services into their flaming dumpsters. That’s awfully convenient, don't you think?
• A Cycle of Renewal, Broken: How Big Tech and Big Media Abuse Copyright Law to Slay Competition: Cable TV exists because of adversarial interoperability, which gave it the power to disrupt the broadcasters. Today, Big Cable is doing everything it can to stop anyone from disrupting it.
• ‘IBM PC Compatible’: How Adversarial Interoperability Saved PCs From Monopolization: IBM spent more than a decade on the wrong end of an antitrust action over its mainframe monopoly, but when it created its first PCs, scrappy upstarts like Phoenix and Compaq were able to clone its ROM chips and create a vibrant, fast-moving marketplace.
• SAMBA versus SMB: Adversarial Interoperability is Judo for Network Effects: Microsoft came this close to owning the modern office by locking up the intranet in a proprietary network protocol called SMB...That is, until a PhD candidate released SAMBA, a free/open product that adversarially interoperated with SMB and allows Macs, Unix systems, and other rivals to live on the same LANs as Windows machines.
• Felony Contempt of Business Model: Lexmark’s Anti-Competitive Legacy: Printer companies are notorious for abusive practices, but Lexmark reached a new low in 2002, when it argued that copyright gave it the right to decide who could put carbon powder into empty toner cartridges. Even though Lexmark failed, it blazed a trail that other companies have enthusiastically followed, successfully distorting copyright to cover everything from tractor parts to browser plugins.
• Mint: Late-Stage Adversarial Interoperability Demonstrates What We Had (And What We Lost): The last great hurrah of Adversarial Interoperability, fought the finance sector...and won!
• Adblocking: How About Nah?: The early Web was infested with intrusive pop-up ads, and adversarial interoperability rendered them invisible. Today, adblocking is the largest boycott in history, doing more to curb bad ads and the surveillance that goes with them than any regulator.
• African WhatsApp Modders are the Masters of Worldwide Adversarial Interoperability: GB WhatsApp started life in the Syrian conflict and is now the leader of the pack in Africa, where it is more popular than Facebook itself -- and where it has to compete with other WhatsApp mods, each customized to a different kind of user and use-case.
• Tracking Exposed: Demanding That the Gods Explain Themselves: How the Tracking Exposed collective uses crowdsourced data to reverse-engineer Big Tech's recommendation algorithms so creators can make sure their subscribers get the videos they asked to see.