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# Android Compatibility # 18 19Android's purpose is to establish an open platform for developers to build 20innovative mobile apps. Three key components work together to realize this 21platform. 22 23The Android Compatibility Program defines the technical details of Android 24platform and provides tools used by OEMs to ensure that developers' apps run 25on a variety of devices. The Android SDK provides built-in tools that 26Developers use to clearly state the device features their apps require. And 27Google Play shows apps only to those devices that can properly run 28them. 29 30These pages describe the Android Compatibility Program and how to get 31access to compatibility information and tools. 32 33## Why build compatible Android devices? ## 34 35### Users want a customizable device. ### 36 37A mobile phone is a highly personal, always-on, always-present gateway to 38the Internet. We haven't met a user yet who didn't want to customize it by 39extending its functionality. That's why Android was designed as a robust 40platform for running after-market applications. 41 42### Developers outnumber us all. ### 43 44No device manufacturer can hope to write all the software that a person could 45conceivably need. We need third-party developers to write the apps users want, 46so the Android Open Source Project aims to make it as easy and open as 47possible for developers to build apps. 48 49### Everyone needs a common ecosystem. ### 50 51Every line of code developers write to work around a particular phone's bug 52is a line of code that didn't add a new feature. The more compatible phones 53there are, the more apps there will be. By building a fully compatible Android 54device, you benefit from the huge pool of apps written for Android, while 55increasing the incentive for developers to build more of those apps. 56 57## Android compatibility is free, and it's easy. ## 58 59If you are building a mobile device, you can follow these steps to make 60sure your device is compatible with Android. For more details about the 61Android compatibility program in general, see [the program overview](overview.html). 62 63Building a compatible device is a three-step process: 64 651. *Obtain the Android software source code*. 66 This is [the source code for the Android platform](/source/index.html), that you port to your hardware. 67 681. *Comply with Android Compatibility Definition Document (CDD)*. 69 The CDD enumerates the software and hardware requirements of a compatible Android device. 70 711. *Pass the Compatibility Test Suite (CTS)*. 72 You can use the CTS (included in the Android source code) as an ongoing aid to compatibility during the development process. 73 74# Joining the Ecosystem # 75 76Once you've built a compatible device, you may wish to include Google 77Play to provide your users access to the third-party app ecosystem. 78Unfortunately, for a variety of legal and business reasons, we aren't able to 79automatically license Google Play to all compatible devices. To inquire 80about access about Google Play, you can [contact us](contact-us.html). 81