Android L is an upcoming release of the Android mobile operating system developed by Google.
Unveiled on June 25, 2014, and released in a beta the next day for selected Google Nexus
devices, it is expected to be released to manufacturing in late-2014.
The most prominent changes to L include a redesigned user interface built around a responsive
design language referred to as "Material Design", and improvements to the notification system
which allow them to be accessed from the lock screen, and displayed within other apps as
banners across the top of the screen.
Internal changes were also made to the platform, with the Android Runtime officially replacing
Dalvik for improved application performance, and changes intended to improve and optimize
battery usage.
Development Android L was first unveiled on June 25, 2014
during a keynote presentation at the Google I/O developers' conference.
Alongside L, the presentation focused on a number of new Android-oriented platforms and
technologies, including Android TV, in-car platform Android Auto, wearable computing
platform Android Wear, and health tracking platform Google Fit.
It does not yet have a formal version number or codename.
Part of the presentation was dedicated to a new cross-platform design language referred
to as "Material Design".
Expanding upon the "card" motifs first seen in Google Now, it is a cleaner design with
increased use of grid-based layouts, responsive animations and transitions, padding, and depth
effects such as lighting and shadows.
Designer Matías Duarte explained that "unlike real paper, our digital material can expand
and reform intelligently.
Material has physical surfaces and edges.
Seams and shadows provide meaning about what you can touch."
The material design language will not only be used on Android, but across Google's suite
of web software as well, providing a consistent experience between applications and platforms.
Features Android L introduces a refreshed notification
system.
Individual notifications are now displayed on cards to adhere to the material design
language, and batches of notifications can be grouped by the app that produced them.
Notifications are now displayed on the lock screen as cards, and notifications can also
be displayed as large banners across the top of the screen, along with their respective
action buttons.
A do-not-disturb feature is also added for notifications.
The recent apps menu was redesigned to use a three-dimensional stack of cards to represent
open apps.
Individual apps can also display multiple cards in the recent menu, rather than only
one entry per app; for example, a web browser can show all of its open tabs as individual
cards.
Android L also contains major new platform features for developers; 5,000 new APIs were
added for use by apps, and the Dalvik virtual machine was officially replaced by Android
Runtime, a new environment introduced as a preview on KitKat.
ART is a cross-platform runtime which supports the x86, ARM, and MIPS architectures in both
32-bit and 64-bit environments.
Unlike Dalvik, which uses just-in-time compilation, ART compiles apps upon installation, which
are then run exclusively from the compiled version from then on.
This technique removes the processing overhead associated with the JIT process, improving
system performance.
Android L also aims to improve battery consumption through a series of optimizations known as
"Project Volta".
Among its changes are a new battery saver mode, job scheduling APIs which can restrict
certain tasks to only occur over Wi-Fi, and batch tasks together to reduce the overall
amount of time that internal radios are active.
The new developer tool "Battery Historian" can be used for tracking battery consumption
by apps while in use.
The Android Extension Pack APIs also provide graphics functions such as new shaders, aiming
to provide PC-level graphics for 3D games on Android devices.
A number of system-level, enterprise-oriented features were also introduced under the banner
"Android for Work": Samsung contributed its Knox security framework for segregating personal
and work-oriented data from each other on a device, along with accompanying APIs for
managing the environment, and bulk app purchases for Google Play Store.
Devices can also be configured so that users can bypass the need to enter an unlock PIN
or pattern can be if it is within a certain geographical location or in proximity to the
user's Android Wear device.
Release A developer preview of Android L was released
for the Nexus 5 and 2013 Nexus 7 on June 26, 2014, as a replacement factory image flashed
in Fastboot mode.
The final release is expected to be made in late-2014.
Source code for the developer preview was released via Android Open Source Project in
July 2014.
HTC has committed to preparing updates to Android L for its HTC One and One M8 smartphones
"within 90 days of receiving final software from Google."
See also Android version history
References