This document aims to help Apache developers understand what they need to do to apply the Apache License, Version 2.0 (ALv2) to Apache software (including source code, documentation, and binary distributions). It is not intended to supplant or otherwise modify any of the terms within the license itself. This is just descriptive guidance and Apache policy is to be found elsewhere.

Information on other Apache-related licenses and updates regarding compatibility with other open source licenses will be posted on Licenses.

Contents

Understanding the 2.0 license

The ALv2 is this set of self-documented copyright and patent licensing terms. The license terms are written in such a way that they can be used by anyone, not just the ASF, and can be applied by reference to the versioned license terms. An appendix to the license describes how this may be done.

Note that the ASF does not use copyright assignment and the copyrights for individual parts of the collective work are retained by the original authors. The method described in the appendix is only suitable for copyright owners. So the ASF uses a variation of this method.

Section 4d of the license provides for attribution notices to be included with a work in a NOTICE file, such that the attribution notices will remain, in some form, within any derivative works. Apache projects MUST include correct NOTICE documents in every distribution.

Applying the license to new software

To apply the ALv2 to a new software distribution, include one copy of the license text by copying the file:

http://www.apache.org/licenses/LICENSE-2.0.txt

into a file called LICENSE in the top directory of your distribution. If the distribution is a jar or tar file, try to add the LICENSE file first in order to place it at the top of the archive. This covers the collective licensing for the distribution.

In addition, a correct NOTICE file MUST be included in the same directory as the LICENSE file.

Each original source document (code and documentation, but excluding the LICENSE and NOTICE files) SHOULD include a short license header at the top. If the distribution contains documents not covered by CLA, CCLA or Software Grant (such as third-party libraries) then see the policy guide.

Updating Existing Software

In brief, the aim is to achieve a final distribution as described above in applying the license to new software. Some conversion tools are listed here.

Frequently Asked Questions (Updates)

Do I have to convert Apache 1.1 licenses to 2.0 licenses in source code?

If the code is owned or distributed by the Apache Software Foundation, then the answer is Yes. The 2.0 license was approved by the ASF board in their January 2004 meeting. As part of that meeting, the board mandated that all ASF software distributions must be converted to the new license by March 1, 2004.

If the code is not owned by the ASF, then the decision is up to the copyright owner. Naturally, we strongly recommend that you upgrade to the new license.

When do I have to convert ASF code to the new license?

All code released after 1 March 2004 must have been converted.

Do I have to convert old versions and branches of code to the new license?

Only if you want the ASF to make a new release of that code after 1 March 2004. "Dead" branches of code do not have to be updated.

Does that mean live branches of code all have to be updated by 1 March 2004?

Code has to be updated prior to any release after 1 March 2004. However code in the source repository can remain under the old 1.1 license until such time as you are ready to perform a release. Note that this applies to any kind of release after 1 March 2004 - including bug fixes.

Frequently Asked Questions (General)

Where Can I Find More Information?

The legal affairs home page.

Where Can I Find Policy?

Follow links from the legal affairs home page.

Where do I find a copy of the new license?

http://www.apache.org/licenses/

Do I have to have a copy of the license in each source file?

Only one full copy of the license is needed per distribution. See the policy.

In my current source files I have attribution notices for other works. Do I put this in each source file now?

See the policy.

No.

Though committers retain copyright, Apache asks that they do not add copyright statements. See the policy for more details.

Can the LICENSE and NOTICE files be called LICENSE.txt and NOTICE.txt?

This is permitted. However the preference is that the files be called LICENSE and NOTICE.

Should the license be included in source files for documentation (e.g. XML that is transformed to HTML)?

Yes. See the policy for more details.