Understanding IPL-1.0: A Comprehensive Guide to the IBM Public License

When it comes to open-source licenses, developers often encounter various options, each with its unique provisions and implications. One such license, the IPL-1.0 or IBM Public License, is specifically tailored for projects associated with IBM. In this article, we will provide an in-depth exploration of IPL-1.0, its key features, and its implications for developers and users alike.

1. The Essence of IPL-1.0:

IPL-1.0, the IBM Public License 1.0, is an open-source license crafted by IBM to govern the distribution and use of its software. Launched in 2001, the license was designed to align with the principles of open source while incorporating specific terms to address IBM’s interests and collaborations.

2. Permissive Yet Specific:

At its core, IPL-1.0 is a permissive license, granting users extensive freedom to use, modify, and distribute the licensed software. Recipients are free to modify the code to suit their needs and share these modifications without imposing any restrictions on other users. However, IPL-1.0 contains specific provisions that make it unique among other permissive licenses.

3. Protective Provisions:

One key feature of IPL-1.0 is its explicit requirement that modified versions of the software must be publicly disclosed. This provision ensures transparency and fosters collaboration, promoting a community-driven approach to software development. Additionally, the license encourages contributors to share their improvements and innovations back with the community.

4. Compliance and Attribution:

IPL-1.0 lays emphasis on compliance with the terms of the license. Developers and users must include the original copyright notice and a disclaimer in their distributions, clearly attributing the work to IBM. This attribution ensures that IBM’s contribution to the project is appropriately recognized.

5. Copyleft Aspect:

While IPL-1.0 is considered permissive, it carries some copyleft characteristics. It requires that any derivative works based on IPL-1.0 licensed software must be distributed under the same IPL-1.0 license terms. This provision ensures that the open-source nature of the original software is preserved, even as it evolves through modifications and contributions.

6. IBM’s Interests and Collaboration:

The IPL-1.0 license is well-suited for projects closely associated with IBM or those that benefit from collaboration with the company. It aligns with IBM’s objective of fostering open innovation and encouraging community-driven development. Developers choosing IPL-1.0 for their projects can leverage IBM’s resources and expertise while contributing to a thriving open-source ecosystem.

7. Compatibility and Dual Licensing:

Developers should be mindful of IPL-1.0’s compatibility with other licenses. Combining IPL-1.0 code with software under different licenses could lead to complexities in distribution and use. If required, developers can choose to dual-license their projects to accommodate specific needs and ensure broader adoption.


In conclusion, IPL-1.0, the IBM Public License, strikes a balance between permissiveness and protective provisions. It empowers developers with extensive freedom to use, modify, and distribute software while ensuring transparency and collaboration within the open-source community. For projects closely tied to IBM’s interests and resources, IPL-1.0 offers a conducive environment for growth and innovation. By understanding the nuances of IPL-1.0, developers can make informed decisions about incorporating it into their projects and contribute to the flourishing open-source landscape.

If you’re interested in exploring a comprehensive list of various open-source licenses and their details, feel free to check out our guide to “Open Source Licenses : A Guide To Software Licensing“. Happy licensing!


  1. “IBM Public License Version 1.0 (IPL-1.0).” Open Source Initiative.
  2. “Understanding Open Source Licenses.” IBM Developer. report/
  3. “IBM and the Principles of the IBM Public License.” IBM Developer.

Please note that the information provided in this article is for informational purposes only and should not be considered legal advice. For specific legal inquiries or to better understand the implications of using the IPL-1.0 license for your projects, it is advisable to consult with a legal professional or licensing expert.

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