Prusa Research has rolled out Open Community License (OCL) v1.1, looking to make open hardware sharing more practical for everyone.
Five months ago, Prusa released the CORE One CAD files under the OCL, and says thousands of projects have since been published under the same license, including work from research groups at UC Berkeley and MIT. But that license usage also brought some questions: how attribution works on a tiny printed part, what “derivative” really means, and how to avoid a maze of incompatible share-alike terms.
OCL v1.1 is now live on GitHub, and Prusa has added it as a selectable license option on Printables. Creators can use the base license as-is, or add new optional “plugins” that attach extra conditions. Importantly, projects previously published under OCL v1.0 remain under that version unless the creator updates them.
A Modular License Built For Mixed Use Cases
The big change is a modular plugin system, something I am not certain has a precedent in open source licensing. Prusa’s thinking: the needs of someone uploading, say, a fan shroud are not the same as a lab releasing years of research, and neither matches a company open-sourcing commercial CAD. OCL v1.1 keeps a short core license and lets licensors “bolt on” plugins to get the licensee behavior they want without having to rewrite the whole agreement.
Four plugins ship with v1.1. General Attribution (GAtt v1) requires credit when derivatives are shared, and it explicitly acknowledges the physical limitations of printed objects by suggesting options like a tag, card, or QR code. It also tries to prevent endless attribution burdens by requiring, at a minimum, credit to the original creator and the creator of the most recent derivative used.
Software Attribution (SWAtt v1) applies similar logic to code, requiring attribution in both the user interface and the source. Micro Business (Micro v1) adds a revenue-threshold concept: organizations under one million euros in annual gross revenue, calculated in a rolling 12-month window and including affiliates, can use the licensed item for internal business purposes without needing a separate business license. A fourth plugin, Research & Development (RnD v1), limits business use to R&D activities and would require a separate agreement for manufacturing.
Plugins are cumulative, meaning a licensor can publish something under “OCL v1.1 + General Attribution + Micro Business” and each plugin’s conditions apply. If this works as intended, it may reduce any pressure creators feel to invent their own custom licenses just to express common requirements like attribution or limited commercial usage.
Tighter Copyleft
Prusa also tightened the copyleft behavior. In OCL v1.0, derivatives could be distributed under “OCL or any non-commercial, share-alike license,” but Prusa says that in practice almost no other license fit cleanly. OCL v1.1 simplifies (and constrains) that: if you distribute a derivative, you distribute it under OCL, reducing license fragmentation across remixes.
The company broadened the definition of business use from “internal production use” to “internal business use,” explicitly including activities like repair, prototyping, optimization, and training. OCL v1.1 also adds language stating it does not override imperative exceptions and limitations under applicable law, and it clarifies the intellectual property scope by explicitly referencing registered designs or design patents, and utility patents.
Alongside the license update, Prusa says it has released printable parts for the INDX upgrade for the CORE One+ under OCL, in addition to the CORE One and CORE One L CAD files. The post also points to OCL adoption outside Printables, including a UC Berkeley volumetric printer project described as projecting images into rotating resin to form parts without layers or supports at extremely high print speeds.
A portion of Prusa’s announcement answers questions that keep popping up about the OCL. Designing an accessory that fits an OCL-licensed product is generally not considered a derivative, unless original licensed geometry is incorporated. Businesses can use OCL-licensed machines and tools to make their own products because that is framed as internal business use, not copying the licensed design. And modifications do not have to be shared unless the modifier chooses to distribute them.
One thing that wasn’t explicitly addressed was open source community comments that the OCL is not actually an open source license. It does restrict free use, unlike a true open source license. However, that’s done to achieve the apparent goal of the OCL: free for some use; not free for big commercial uses.
