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