Title: Applying the Apache License, Version 2.0
Notice:    Licensed to the Apache Software Foundation (ASF) under one
           or more contributor license agreements.  See the NOTICE file
           distributed with this work for additional information
           regarding copyright ownership.  The ASF licenses this file
           to you under the Apache License, Version 2.0 (the
           "License"); you may not use this file except in compliance
           with the License.  You may obtain a copy of the License at
           .
             http://www.apache.org/licenses/LICENSE-2.0
           .
           Unless required by applicable law or agreed to in writing,
           software distributed under the License is distributed on an
           "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
           KIND, either express or implied.  See the License for the
           specific language governing permissions and limitations
           under the License.

This document aims to help Apache developers understand what they need to do
to apply the [Apache License, Version
2.0](http://www.apache.org/licenses/LICENSE-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](http://www.apache.org/legal).

Information on other Apache-related licenses and updates regarding compatibility
with other [open source](http://www.opensource.org) licenses will be posted on 
[Licenses](http://www.apache.org/licenses/).

[TOC]

Contents
--------

# Understanding the 2.0 license # {#license}

The ALv2 is [this](http://www.apache.org/licenses/LICENSE-2.0.txt) 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](http://www.apache.org/licenses/LICENSE-2.0.html#apply).
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](http://www.apache.org/licenses/LICENSE-2.0.txt)
provides for attribution notices to be included with a work in a 
[NOTICE](http://www.apache.org/licenses/example-NOTICE.txt) file, such that 
the attribution notices will remain, in some form, within any derivative works.
Apache projects [MUST](http://www.apache.org/legal/src-headers.html#notice)
include correct NOTICE documents in every distribution.  


# Applying the license to new software # {#new}

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](http://www.apache.org/legal/src-headers.html#notice)
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](http://www.apache.org/legal/src-headers.html#headers)
include a short license header at the top. If the distribution contains 
documents not covered by [CLA](http://www.apache.org/licenses/icla.txt),
[CCLA](http://www.apache.org/licenses/cla-corporate.txt) or
<a href='http://www.apache.org/licenses/software-grant.txt'>Software Grant</a>
(such as third-party libraries) then see the
<a href='http://www.apache.org/legal/3party.html'>policy guide</a>.


# Updating Existing Software # {#existing}

In brief, the aim is to achieve a final distribution as described above in
[applying the license to new software](#new). Some conversion tools are 
listed [here](http://www.apache.org/legal/src-headers.html#faq-update-scripts).


# Frequently Asked Questions (Updates) # {#faq-existing}

## Do I have to convert Apache 1.1 licenses to 2.0 licenses in source code? ## {#convert_to_2_0}

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? ## {#convert-all}

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? ## {#conversion}

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? ## {#deadline}

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) # {#faq}

## Where Can I Find More Information? ## {#info-whereis}

The legal affairs [home page](http://www.apache.org/legal).

## Where Can I Find Policy? ## {#policy-whereis}

Follow links from the legal affairs [home page](http://www.apache.org/legal).

## Where do I find a copy of the new license? ## {#license-whereis}

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

## Do I have to have a copy of the license in each source file? ## {#copy-per-file}

Only one full copy of the license is needed per distribution.
See the [policy](http://www.apache.org/legal/src-headers.html).

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

See the [policy](http://www.apache.org/legal/src-headers.html).

## Can/Should individual committers added copyright statements to the NOTICE or source code files? ## {#contributor-copyright}

No.

Though committers retain copyright, Apache asks that they do not add copyright
statements.  See the [policy](http://www.apache.org/legal/src-headers.html)
for more details.

## Can the LICENSE and NOTICE files be called LICENSE.txt and NOTICE.txt? ## {#license-file-name}

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)? ## {#license-include}

Yes. See the [policy](http://www.apache.org/legal/src-headers.html) for more
details.

*[ALv2]: Apache License, Version 2.0
*[ASF]: Apache Software Foundation
*[CLA]: Individual Contributor License Agreement
*[CCLA]: Corporate Contributor License Agreement