1 page.title=Licenses 2 @jd:body 3 4 <!-- 5 Copyright 2010 The Android Open Source Project 6 7 Licensed under the Apache License, Version 2.0 (the "License"); 8 you may not use this file except in compliance with the License. 9 You may obtain a copy of the License at 10 11 http://www.apache.org/licenses/LICENSE-2.0 12 13 Unless required by applicable law or agreed to in writing, software 14 distributed under the License is distributed on an "AS IS" BASIS, 15 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 See the License for the specific language governing permissions and 17 limitations under the License. 18 --> 19 <div id="qv-wrapper"> 20 <div id="qv"> 21 <h2>In this document</h2> 22 <ol id="auto-toc"> 23 </ol> 24 </div> 25 </div> 26 27 <p>The Android Open Source Project uses a few 28 <a href="http://www.opensource.org/">open source initiative</a> 29 approved open source licenses for our software.</p> 30 <h2 id="android-open-source-project-license">Android Open Source Project License</h2> 31 <p>The preferred license for the Android Open Source Project is the 32 <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache 33 Software License, Version 2.0</a> ("Apache 2.0"), 34 and the majority of the Android software is licensed 35 with Apache 2.0. While the project will strive to adhere to the preferred 36 license, there may be exceptions that will be handled on a case-by-case 37 basis. For example, the Linux kernel patches are under the GPLv2 license with 38 system exceptions, which can be found on <a href="http://www.kernel.org/pub/linux/kernel/COPYING">kernel.org</a>.</p> 39 <h2 id="contributor-license-grants">Contributor License Grants</h2> 40 <p>All <em>individual</em> contributors (that is, contributors making contributions 41 only on their own behalf) of ideas, code, or documentation to the Android Open 42 Source Project will be required to complete, sign, and submit an <a href="cla-individual.html">Individual 43 Contributor License Grant</a>. The grant can be executed online through the 44 <a href="https://android-review.googlesource.com/#/settings/agreements">code review tool</a>. 45 The grant clearly defines the terms under which intellectual 46 property has been contributed to the Android Open Source Project. This license 47 is for your protection as a contributor as well as the protection of the 48 project; it does not change your rights to use your own contributions for any 49 other purpose.</p> 50 <p>For a <em>corporation</em> (or other entity) that has assigned employees to 51 work on the Android Open Source Project, a <a href="cla-corporate.pdf">Corporate 52 Contributor License Grant</a> is available. 53 This version of the grant allows a 54 corporation to authorize contributions submitted by its designated employees 55 and to grant copyright and patent licenses. Note that a Corporate Contributor 56 License Grant does not remove the need for any developer to sign their own 57 Individual Contributor License Grant as an individual. The individual grant is needed 58 to cover any of their contributions that are <em>not</em> owned by the corporation signing the 59 Corporate Contributor License Grant.</p> 60 <p>Please note we based our grants on the ones the 61 <a href="http://www.apache.org">Apache Software Foundation</a> uses, which can 62 be found on the <a href="http://www.apache.org/licenses/">Apache web site</a>.</p> 63 <h2 id="why-apache-software-license">Why Apache Software License?</h2> 64 <p>We are sometimes asked why Apache Software License 2.0 is the preferred 65 license for Android. For userspace (that is, non-kernel) software, we do in 66 fact prefer ASL2.0 (and similar licenses like BSD, MIT, etc.) over other 67 licenses such as LGPL.</p> 68 <p>Android is about freedom and choice. The purpose of Android is promote 69 openness in the mobile world, and we don't believe it's possible to predict or 70 dictate all the uses to which people will want to put our software. So, while 71 we encourage everyone to make devices that are open and modifiable, we don't 72 believe it is our place to force them to do so. Using LGPL libraries would 73 often force them to do just that.</p> 74 <p>Here are some of our specific concerns:</p> 75 <ul> 76 <li> 77 <p>LGPL (in simplified terms) requires either: shipping of source to the 78 application; a written offer for source; or linking the LGPL-ed library 79 dynamically and allowing users to manually upgrade or replace the library. 80 Since Android software is typically shipped in the form of a static system 81 image, complying with these requirements ends up restricting OEMs' designs. 82 (For instance, it's difficult for a user to replace a library on read-only 83 flash storage.)</p> 84 </li> 85 <li> 86 <p>LGPL requires allowance of customer modification and reverse 87 engineering for debugging those modifications. Most device makers do 88 not want to have to be bound by these terms. So to minimize the burden on 89 these companies, we minimize usage of LGPL software in userspace.</li></p> 90 </li> 91 <li> 92 <p>Historically, LGPL libraries have been the source of a large number 93 of compliance problems for downstream device makers and application 94 developers. Educating engineers on these issues is difficult and slow-going, 95 unfortunately. It's critical to Android's success that it be as easy as 96 possible for device makers to comply with the licenses. Given the 97 difficulties with complying with LGPL in the past, it is most prudent to 98 simply not use LGPL libraries if we can avoid it.</p> 99 </li> 100 </ul> 101 <p>The issues discussed above are our reasons for preferring ASL2.0 for 102 our own code. They aren't criticisms of LGPL or other licenses. We are 103 passionate about this topic, even to the point where we've gone out of our 104 way to make sure as much code as possible is ASL2.0 licensed. However, we love all free 105 and open source licenses, and respect others' opinions and preferences. We've 106 simply decided ASL2.0 is the right license for our goals.</p> 107
