1 page.title=Licenses 2 doc.type=source 3 @jd:body 4 <div> 5 <p>The Android Open Source Project uses a few <a 6 href="http://www.opensource.org/">open source initiative</a> approved open 7 source licenses for our software.</p> 8 <h2>Android Open Source Project license</h2> 9 <p>The preferred license for the Android Open Source Project is the <a 10 href="http://www.apache.org/licenses/LICENSE-2.0">Apache Software License, 11 2.0</a> ("Apache 2.0"), and the majority of the Android software is licensed 12 with Apache 2.0. While the project will strive to adhere to the preferred 13 license, there may be exceptions which will be handled on a case-by-case 14 basis. For example, the Linux kernel patches are under the GPLv2 license with 15 system exceptions, which can be found on <a 16 href="http://www.kernel.org/pub/linux/kernel/COPYING">kernel.org</a>. 17 </p> 18 <h2>Contributor License Grants</h2> 19 <p>All <b>individual</b> contributors (that is, contributors making contributions 20 only on their own behalf) of ideas, code, or documentation to the Android Open 21 Source Project will be required to complete, sign, and submit an <a 22 href="{@docRoot}source/cla-individual.html">Individual 23 Contributor License Grant</a>. The grant can be executed online through the <a 24 href="https://review.source.android.com/#settings,agreements">code review 25 tool</a>. The grant clearly defines the terms under which intellectual 26 property has been contributed to the Android Open Source Project. This license 27 is for your protection as a contributor as well as the protection of the 28 project; it does not change your rights to use your own contributions for any 29 other purpose.</p> 30 <p>For a <b>corporation</b> (or other entity) that has assigned employees to 31 work on the Android Open Source Project, a <a 32 href="{@docRoot}source/cla-corporate.html">Corporate 33 Contributor License Grant</a> is available. This version of the grant allows a 34 corporation to authorize contributions submitted by its designated employees 35 and to grant copyright and patent licenses. Note that a Corporate Contributor 36 License Grant does not remove the need for any developer to sign their own 37 Individual Contributor License Grant as an individual, to cover any of their 38 contributions which are <b><i>not</i></b> owned by the corporation signing the 39 Corporate Contributor License Grant. 40 </p> 41 <p>Please note that we based our grants on the ones that the <a 42 href="http://www.apache.org/">Apache Software Foundation</a> uses, which can 43 be found on <a href="http://www.apache.org/licenses/">the Apache web site</a>.</p> 44 <h2>Why Apache Software License?</h2> 45 <p>We are sometimes asked why Apache Software License 2.0 is the preferred 46 license for Android. For userspace (that is, non-kernel) software, we do in 47 fact prefer ASL2.0 (and similar licenses like BSD, MIT, etc.) over other 48 licenses such as LGPL.</p> 49 <p>Android is about freedom and choice. The purpose of Android is promote 50 openness in the mobile world, but we don't believe it's possible to predict or 51 dictate all the uses to which people will want to put our software. So, while 52 we encourage everyone to make devices that are open and modifiable, we don't 53 believe it is our place to force them to do so. Using LGPL libraries would 54 often force them to do so.</p> 55 <p>Here are some of our specific concerns:</p> 56 <ol> 57 <li>LGPL (in simplified terms) requires either: shipping of source to the 58 application; a written offer for source; or linking the LGPL-ed library 59 dynamically and allowing users to manually upgrade or replace the library. 60 Since Android software is typically shipped in the form of a static system 61 image, complying with these requirements ends up restricting OEMs' designs. 62 (For instance, it's difficult for a user to replace a library on read-only 63 flash storage.)</li> 64 <li>LGPL requires allowance of customer modification and reverse 65 engineering for debugging those modifications. Most device makers do 66 not want to have to be bound by these terms, so to minimize the burden on 67 these companies we minimize usage of LGPL software in userspace.</li> 68 <li>Historically, LGPL libraries have been the source of a large number 69 of compliance problems for downstream device makers and application 70 developers. Educating engineers on these issues is difficult and slow-going, 71 unfortunately. It's critical to Android's success that it be as easy as 72 possible for device makers to comply with the licenses. Given the 73 difficulties with complying with LGPL in the past, it is most prudent to 74 simply not use LGPL libraries if we can avoid it.</li> 75 </ol> 76 <p>The issues discussed above are our reasons for preferring ASL2.0 for 77 our own code. They aren't criticisms of LGPL or other licenses. We do 78 feel strongly on this topic, even to the point where we've gone out of our 79 way to make sure as much code as possible is ASL2.0. However, we love all free 80 and open source licenses, and respect others' opinions and preferences. We've 81 simply decided that ASL2.0 is the right license for our goals.</p> 82 </div> 83
