You are in my Digital Garden.

Software Licensing

Last modified: Dec 10th, 2025

Classic opensource licenses

These include MIT, GPL, etc. See choosealicense.com to learn about those.

New licenses

These are not new as in “created this year”, but are part of a “new generation” of licenses, created in this millenium.

Professional

These licenses were written by lawyers and are intended to withstand real usage in the market and in court.

• License Zero / Artless Devices licenses (as of Sep 2023)
  • Kyle Mitchell is involved (this is a good thing)
  • Parity Public License - requires users who build with your software to share their work
  • Prosperity Public License - free for noncommercial use, with a built-in free trial for commercial users
    • GitHub uses this for Dependabot Core
• The Polyform Project
  • Kyle Mitchell is involved
  • PolyForm Noncommercial - a general noncommercial-only license for software
    • No free trial unlike Prosperity license above
  • PolyForm Small Business permits use by small businesses and other small organizations
  • More licenses available on the website: noncompete, strict, free trial, internal
• Big Time License
  • By Kyle Mitchell
  • Makes software free for noncommercial and small-business use, with a guarantee that fair paid terms are available to everyone else
  • Fair terms have certain requirements (see license text for exact details)
    • Commercial licenses and pricing are advertised
    • Licensor offers terms and price as advertised
    • Previous customer has bought a commercial license on similar terms in the past year
    • Presumably if the last requirement is not possible, things can still be considered fair by offering advertised prices
• Blue Oak Model License
  • Kyle Mitchell is involved (Executive Director)
  • Permissive license, like MIT
  • “state-of-the-art”
  • Claims to be “easier to read and more legally complete” than any other permissive license
  • More details in their blog post
• Functional Source License (FSL)
  • Like a permissive license, except you can’t use the code to offer a competing product
  • After two years the license switches to MIT or Apache 2.0

Deterrents

These licenses are usually not written by lawyers, and have requirements that are legally unusual. They may not be enforceable in a court of law, but they will definitely scare away legally rigorous organizations.

• Anti-Capitalist Software License
  • “This license exists to release software that empowers individuals, collectives, worker-owned cooperatives, and nonprofits, while denying usage to those that exploit labor for profit.”
• Nonviolent Public License and derivatives
  • I have not read these
  • Acronyms for licenses: NVPL, CNPL, NVPL-NA, CNPL-NA
• The Hippocratic License
  • Extensive and far-reaching license builder for enforcing ethics on software users
  • Not sure who created it or their credentials, or how legally viable it is
• For more of these, see funputer.biz - Licenses, by Case Duckworth / acdw

Resources

• Don’t use the LGPL for Go code - by me
• Blue Oak Council
• Kyle Mitchell’s blog
• DualLicensing.com
• Post-Open Source - great blog post by boringcactus about FOSS and software licensing
• Open Source Licensing - from Boris Mann’s digital garden
• Contributing to Public-Private Licensing Projects - how to deal with contributions when selling paid licenses
• Open Source Power by Erlend
• Fair Source - software sharing for businesses