LLVM Relicensing Effort

The LLVM relicensing effort aims to modernize the LLVM Licensing structure and developer policy. The high level goals of the relicensing effort are to:

  • Encourage ongoing contributions to LLVM by preserving a low barrier to entry for contributors
  • Protect users of LLVM code by providing explicit patent protection in the license
  • Protect contributors to the LLVM project by explicitly scoping their patent contributions with this license
  • Eliminate the schism between runtime libraries and the rest of the compiler that makes it difficult to move code between them
  • Ensure that LLVM runtime libraries may be used by other open source and proprietary compilers

This project involves sensitive legal issues and has been a multi-year effort. The primary public discussions have included these mailing list threads:

Beyond that, these topics have also been discussed by, and include contributions from, over a dozen lawyers and key LLVM contributors, and have been discussed informally with hundreds of people in the LLVM Developer Meeting BoFs. The effort has been overseen by Heather Meeker, who is the LLVM Foundation’s legal counsel. If you have questions or concerns about the content of this document, please email the llvm-dev mailing list or the LLVM Foundation Board depending on the sensitivity of your email.

Status and Documents

At this point, we have achieved community consensus on:

We also have worked with our legal counsel to build several more boring pieces:

  • A new top-of-file header block that is minimal and includes the relevant and important information about the new license
  • An individual agreement to relicense and a form to collect information necessary for completing the relicensing
  • A corporate agreement to relicense that is available for companies to sign and has begun to be distributed to some of the known and/or large contributors

The new license was added and changes to the developer policy were completed on January 19, 2019 after the LLVM 8.0 release was branched.

We are currently collecting relicensing agreements from copyright holders of contributions before 19th of January 2019. While we already have well over 90% of code covered, we are still working through the long tail. We are seeking volunteers to help us reach individuals and corporations who have not signed the relicense agreements. For full details on how to help, please see our long tail relicensing page for more details.

Once the codebase is fully covered by the new license, we’ll drop the old license.

New File Header

The new file header is:

//===-- file/name - File description ----------------------------\*- C++ -\*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

Some notable aspects of the new header:

  • There is no explicit copyright notice – these had little value and tended to not be maintained

  • It is designed to be as compact and minimalist as possible while having the critical information: that it is part of LLVM, what license it is under, where to find that license, and the machine-scrapable SPDX markup to help people doing license audits

Individual Relicensing Agreement

Individuals need to complete a web form that we use to drive the relicensing process. Part of that form will prompt them with a DocuSign agreement that they can sign online to cover anything they personally contributed. It will also collect any companies or academic institutions that may own right to some of their contributions so that we can cover them with the corporate agreement below.

We do ask that individuals generally sign the individual agreement even if they think their contributions are probably covered by a corporate agreement.

Feel free to send questions concerns about this to the Foundation mailing list.

Corporate Relicensing Agreement

Corporations may sign an agreement to relicense their contributions to LLVM under the new license with DocuSign . This is our preferred mechanism for collecting signatures. However, if your company requires it, you can print out this PDF of the agreement , sign it, scan it, and send the signed version as a PDF attachment to the LLVM Foundation Board. Further, if your company has a specific concern or issue with the agreement, please reach out to the the board and we’ll try to help.

Companies that have Signed:

A list of companies that have been contacted about relicensing is below. This is primarily intended to avoid duplicate work within these companies trying to get things signed and set up.