Verified — Opl-1 License

Distribution of the work or derivatives in standard paper book form is prohibited without prior permission.

The document must point to the location of the original, unmodified text. opl-1 license

The license permits translation, compilation, and modification. Requirements for Modified Works Distribution of the work or derivatives in standard

If you search GitHub today for "OPL-1," you will find fewer than 500 public repositories (compared to millions for MIT). Most are inactive. Notable historical uses include: Requirements for Modified Works If you search GitHub

There is exactly scenario where OPL-1 makes sense: You are building a completely standalone application from scratch, using no third-party libraries except other OPL-1 code, and you are philosophically opposed to the FSF (Free Software Foundation) but still want strong copyleft. In that case, OPL-1 is an option. But for 99.9% of developers, this is a thought experiment, not a practical reality.

Often confused with other similarly named licenses (such as the Open Software License or the Academic Free License), the OPL-1 represents a specific moment in the evolution of open source: a time when legal scholars were actively experimenting with how to enforce attribution and responsibility through contract law rather than just copyright law.