1page.title=Philosophy and Goals 2doc.type=about 3doc.hidenav=true 4@jd:body 5<p>Android is an open-source software stack for mobile phones and similar 6devices.</p> 7<h2>Origin and Goal</h2> 8<p>Android was originated by a group of companies known as the Open Handset 9Alliance, led by Google. Today, many companies -- both original members of the 10OHA and others -- have invested heavily in Android, typically in the form of 11allocating significant engineering resources to improve Android and bring 12Android devices to Market.</p> 13<p>We created Android in response to our own experiences launching mobile 14apps. We wanted to make sure that there would always be an open platform 15available for carriers, OEMs, and developers to use to make their innovative 16ideas a reality. We wanted to make sure that there was no central point of 17failure, where one industry player could restrict or control the innovations 18of any other. The solution we chose was an open and open-source platform.</p> 19<p>But the ultimate goal, of course, is to improve the mobile experience for 20real users by facilitating innovation. Accordingly, the primary goal of the 21AOSP is to make sure Android is a success as an end user product.</p> 22<h2>Governance Philosophy</h2> 23<p>The companies that have invested in Android have done so on its merits, 24because we collectively believe that an open platform is necessary. Android is 25intentionally and explicitly an open-source -- as opposed to free software -- 26effort: a group of organizations with shared needs has pooled 27resources to collaborate on a single implementation of a shared product. 28The Android philosophy is pragmatic, first and foremost. The objective is 29a shared product that each contributor can tailor and customize.</p> 30<p>Uncontrolled customization can, of course, lead to incompatible 31implementations. To prevent this, the AOSP also maintains the Android 32Compatibility Program, which spells out what it means to be "Android 33compatible", and what is required of device builders to achieve that status. 34Anyone can (and will!) use the Android source code for any purpose, and we 35welcome all such uses. However, in order to take part in the shared 36ecosystem of applications that we are building around Android, device builders 37can take advantage of the Compatibility Program.</p> 38<p>Though Android consists of multiple sub-projects, this is strictly a 39project-management technique. We view and manage Android as a single, 40holistic software product, not a "distribution", specification, or collection 41of replaceable parts. Conceptually, our notion is that device builders port 42Android to a device; they don't implement a specification or curate a 43distribution.</p> 44<h2>How We Work</h2> 45<p>We know that quality does not come without hard work. Along with many 46partners, Google has contributed full-time engineers, product managers, UI 47designers, Quality Assurance, and all the other roles required to bring 48modern devices to market. We integrate the open source administration and 49maintenance into the larger product development cycle.</p> 50<p>In a nutshell:</p> 51<ul> 52<li>At any given moment, there is a current latest release of the Android 53platform. This typically takes the form of a branch in the tree.</li> 54<li>Device builders and Contributors work with the current 55latest release, fixing bugs, launching new devices, experimenting with new 56features, and so on.</li> 57<li>In parallel, Google works internally on the next version of the 58Android platform and framework, working according to the product's needs and 59goals. Some of the work from the current latest tree will promoted into these 60releases.</li> 61<li>When the "n+1"th version is determined to be nearing completion, it will 62be published to the public source tree, and become the new latest 63release.</li> 64<li>Since Android is open source, nothing prevents device implementers from 65shipping devices on older (obsolete) Android builds. However, active work will 66be focused on the current platform release.</li> 67</ul> 68<p>To meet our goals, Android needs to achieve widespread, compatible 69adoption. We believe that the best way to accomplish that is to make sure that 70we ship high-quality, flagship devices with an intense product and end-user 71focus. The "next release" of Android is driven by the product needs for the next 72generation of mobile devices; the resulting excellent product is then released 73to open source and becomes the new current version of the platform.</p> 74