Competitive compatibility is a term used by Cory Doctorow — often interchangeably with adversarial-interoperability — to describe the practice of building products that work with competing products or platforms without requiring the incumbent's consent. Where "adversarial interoperability" emphasizes the conflict with incumbents who resist such compatibility, "competitive compatibility" foregrounds the market effect: competition is made possible through compatibility.
Framing and Distinction
The two terms describe the same underlying phenomenon but carry different rhetorical emphases:
Doctorow uses both, and the choice is often contextual. In technical and policy papers, "competitive compatibility" may appear when the audience is legal or regulatory; "adversarial interoperability" tends to dominate in his more polemical writing on pluralistic-blog.
Historical Logic
The competitive-compatibility argument centers on a historical claim: throughout much of computing history, new entrants gained market footholds by being compatible with incumbent products — reading their file formats, emulating their protocols, connecting to their networks. This compatibility was typically unilateral and uninvited. It enabled competition in markets that would otherwise have been winner-take-all due to network effects.
Doctorow catalogues examples: email clients competing with each other because SMTP is an open protocol; web browsers competing because HTML is a standard; early office software competing by reading each other's files. In each case, competitive compatibility was the mechanism through which users could move between products without sacrificing their accumulated data and connections.
The argument is that today's platform markets have broken this mechanism. Google, Apple, Amazon, and Meta have used legal and technical tools to prevent competitive compatibility with their services — meaning new entrants cannot build on top of incumbents' networks, users cannot bring their data or social graphs when switching, and switching-costs are engineered to be prohibitive.
Policy Implications
Competitive compatibility connects directly to interoperability-mandates: if competitive compatibility would naturally discipline incumbent platforms but is being actively blocked, regulatory intervention to require interoperability restores the competitive dynamic. This is the argument Doctorow makes in the-internet-con — interoperability mandates are not about government micromanagement of technology but about restoring the conditions for competition that incumbents have suppressed.
The concept also bears on digital-rights-management-critique: DRM is one of the primary tools incumbents use to prevent competitive compatibility, by making circumvention illegal under statutes like the DMCA.
Relationship to Broader Antitrust Analysis
lina-khan, tim-wu, and matt-stoller have each engaged with related concepts in antitrust contexts. The competitive-compatibility framing maps well onto "essential facilities" doctrine in antitrust law — the argument that dominant platforms controlling essential infrastructure must provide access on fair terms. Doctorow does not always use antitrust vocabulary, but his argument is structurally compatible with it.