An open license or free license is a license that allows others to re-use an author's work as they wish. Without such a license, such use is generally prohibited by copyright law or a closed license.

• Public domain licenses
  • Creative Commons CC0
  • WTFPL
  • Unlicense
  • Public Domain Dedication and License (PDDL)^[1]
• Permissive licenses
  • BSD License
  • MIT License
  • Mozilla Public License (file-based permissive copyleft)
  • Creative Commons Attribution
• Copyleft & patentleft licenses
  • GNU GPL, LGPL (weaker copyleft), AGPL (stronger copyleft)
  • Creative Commons Attribution Share-Alike
  • Mozilla Public License
  • Common Development and Distribution License
  • GFDL (without invariant sections)
  • Free Art License

• Open-source software
  • The Open Source Definition
• Open Content
  • Open Content License
  • Open Publication License
• Open-source hardware
• Open database
  • Creative Commons v4
  • Open Database Licence

• Creative Commons
• Free Software Foundation
• Open Source Initiative
• Microsoft
  • Microsoft Public License
  • Microsoft Reciprocal License
• Open Content Project
• Open Data Commons from Open Knowledge Foundation
  • Public Domain Dedication and License (PDDL)
  • Attribution License (ODC-By)
  • Open Database License (ODC-ODbL)
• European Union
  • European Union Public Licence

• Open content
• Openness