Using the Processing core library in .jar format in my now-MIT-licensed Java program

Processing
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I have a Java program that used the Processing core.jar as a library to function.

I want to use the MIT license.

How do I license this properly?

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Hi @LangdonS and thanks for your question.

You can license your own code under MIT while using Processing’s core.jar (LGPL 2.1), as long as:

  • You don’t modify core.jar.
  • You dynamically link core.jar (e.g., keep it as a separate .jar or use it as a Maven dependency).
  • You include the LGPL 2.1 license and inform your users that your software links an LGPL-licensed component.
  • You make it possible for users to replace core.jar, if they choose.

This lets you keep your code under MIT while respecting LGPL requirements.

Please also consult the full LICENSE.md for more details as some other licenses may apply to Processing core dependencies.

Note that I am not a lawyer or a licensing expert and that this is not legal advice.

1 Like
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" …inform your users that your software links an LGPL-licensed component."

What do you mean exactly?

In the LICENSE file (the one with the MIT license)?

4

The LGPL doesn’t prescribe exactly how to do it, just that you must give a “prominent notice” that your software uses the Library and that it’s covered by the LGPL.

In Section 6 it says:

You must give prominent notice with each copy of the work that the Library is used in it and that the Library and its use are covered by this License.

Note that this is a separate requirement from including a copy of the full license text.

For a clear summary of LGPL 2.1 requirements, see: GNU Lesser General Public License v2.1 (LGPL-2.1) Explained in Plain English - TLDRLegal

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How’s this?:
“This app makes use of the Processing core library, licensed under the LGPL v2.1”