I used to prefer permissive licenses and now favor copyleft

Scope of the debate

• Thread centers on whether shifting from permissive to copyleft licenses better serves users, developers, and society, with substantial disagreement on both practical and ethical grounds.
• Many comments treat Vitalik’s shift as part of a broader re‑evaluation of permissive licensing in the age of cloud platforms and AI.

Reasons given for preferring permissive licenses

• Some developers care mainly about immediate users and downstream developers, not broader social effects; they want minimum friction and obligations.
• Permissive bases enable closed-source add‑ons and tooling businesses that wouldn’t exist (or be viable) under strong copyleft; this is framed as expanding the ecosystem and accessibility for non‑programmer users.
• Companies often forbid GPL; permissive licensing is seen as the only way to get widespread corporate adoption, contributions, and sponsorship.
• Some view their code as an unconditional “gift to the commons” and see copyleft conditions as hypocritical or authoritarian.

Reasons given for preferring copyleft / critiques of permissive

• Copyleft is framed as caring for users’ long‑term freedom: preventing popular improvements from disappearing into proprietary forks or embrace‑extend‑extinguish scenarios.
• Permissive licenses are repeatedly described as subsidizing big business and “dead branches” of proprietary code that don’t return value to the commons.
• Several argue that permissive licenses benefit large firms far more than small ones, who can’t compete when their own work is productized against them.
• Objection: “no one is harmed by permissive licenses” is challenged with examples where users of proprietary forks lose the ability to inspect, modify, and repair.

GPL, legal uncertainty, and alternatives

• Strong disagreements over how GPL/AGPL apply to linking, plugins, and “infection”; some describe the text as vague and litigation‑prone, others say myths and corporate FUD exaggerate the risks.
• Some report that GPL scares corporate users; others would rather forgo that adoption than enable proprietary restriction of users.
• MPLv2 is praised as a pragmatic middle ground; LGPL and its static-linking obligations are seen as awkward for languages with heavy codegen/templates.
• SSPL and similar “anti‑cloud” licenses are discussed as attempts to defend against hyperscalers, though their status as “free/open source” is contested.

Licensing and AI training

• Multiple comments argue that copyleft (as written) is ill‑suited to AI and SaaS; calls appear for a GPLv4 or variants with no‑AI or stronger network-use clauses.
• Others respond that copyright and fair‑use doctrines themselves may be failing against AI, making license clauses hard to enforce.

Broader context: diffusion and “theft”

• Historical industrial espionage and copyright avoidance are cited to argue that technology diffusion (often via “theft”) has always driven growth, complicating strict pro‑property or anti‑copy narratives.