pdk/docs/about/philosophy.jd

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