Google announced Android 4.1 at Google I/O today. With "Project Butter," the operating system has become faster and smoother, with an emphasis on smooth animations throughout.

The company has added what it calls "delightful improvements" to make the platform more pleasurable to use. Widget organization on the home screens has been enhanced with automatic repositioning and resizing, text input has been enhanced with a keyboard that predicts what you're typing before you even type it, and the operating system includes offline speech recognition.

Searching has also been extensively expanded, with rich semantic information courtesy of Google's knowledge graph, natural language voice search, and "Google Now," an automatic contextual search service that will tell you about appointments, flights, your daily commute, or anything else that you've recently searched for.

In "Project Butter," Google has worked to improve graphical performance and touch responsiveness. On the graphics side, Android is now v-synced at 60 frames a second, with triple-buffered graphics. The result is that scrolling, paging, and animations are all smoother and consistent.

To make touch feel better, Google is making it anticipatory, so that the touch data applications receive corresponds to where fingers will be the next time the screen is redrawn. This means that apps won't have to be one step behind where the user's fingers actually are. Jelly Bean will also immediately ramp CPUs to their full speed whenever touch interaction is detected. This avoids lag caused by slower processing when the CPUs are in low power modes.

For developers, the Jelly Bean SDK will include a new profiling tool, systrace, that provides a clear visualization of their applications' use of the CPU, GPU, and other system components, so that bottlenecks can be more readily identified and resolved.

Google showed off a handful of user interface improvements that it says will make using Android 4.1 more pleasing and will make the operating system accessible to more markets and more users.

Homescreen widget management has been enhanced to make customizing and organizing the homescreen much slicker. Widgets will intelligently move out of the way when new widgets are being added and moved, and will resize themselves if they're too large for the space available.

Text input has been improved in numerous ways. Google has improved its support for Arabic and Hebrew, and added new support for Persian, Hindi, and Thai. The on-screen keyboard has a better dictionary and has greater prediction: it will guess at entire words, based on the words already typed.

Voice recognition has also been enhanced; though it will use the cloud if an Internet connection is available, Android 4.1 also includes an offline speech-to-text engine that will perform speech recognition when the cloud is unavailable.

Jelly Bean should also be better for blind and partially sighted users. The operating system should be usable through a combination of gestures and speech, and can be paired with Bluetooth Braille devices.

Picture management through the camera application has been made simpler with a panning layout that allows you to swipe unwanted photos away.

Though NFC still isn't found on most Android phones, Google is working to make it more useful. Android Beam in Jelly Bean allows sharing of photos and videos just by tapping phones together, and Android 4.1 can now pair to combined NFC-Bluetooth devices such as headsets and speakers just by tapping the phone against the devices.

Notifications, already a strong point of the platform, have also seen a lot of improvement. Notifications can now be interactive—for example, allowing calls to be made and hung up directly from a missed call notification. They can also be expanded to show more detailed information without having to tap through and go into an actual application.

Search has also seen substantial work. Google recently rolled out its knowledge graph search features for Web users. The knowledge graph allows the search engine to provide rich semantic information in response to queries: it knows, for example, that "Angelina Jolie" is an actress who has made a number of movies, and can show you appropriate information about her career and the films she is in.

Jelly Bean includes these same capabilities in its search tool; a search for Angelina will show you a card with her picture, vital information, and recent releases. Similar information cards are available for searches about weather, restaurants, and more. Voice searching has also been improved, with the ability to read answers back to you and smarter responses to natural language queries.

The biggest new feature is "Google Now." With Google Now, the phone will pay attention to information such as where it is, what you've searched for, and what appointments you have, and every time you go into the search widget, it will provide relevant contextual information.

For example, if you have a meeting coming up in an hour, Google Now might tell you travel information on how to get there. If it is around the time you make your daily commute, the program will check out the traffic automatically, and if it's looking bad, it will suggest an alternative route. If you go abroad, it will give instant access to currency conversions and tell you the local time back home.

Last but by no means least, Google has announced a new Platform Developer Kit (PDK) for OEMs, processor companies, and everyone else involved in the actual making of Android phones and tablets. Timely availability of updates has long been an annoyance with the Android platform, as the system builders have to do a lot of work to update and customize their distributions of the operating system.

PDKs will, in the future, ship two to three months before new versions of the operating system are made available and should contain all the software and information that these companies need to prepare for the impending releases. In principle, this should make the timely delivery of Android updates faster and easier. Google has been developing a beta PDK for Android 4.1 with select partners.

Android 4.1 will be made available to the Galaxy Nexus, Motorola Xoom, and Nexus S over-the-air from mid-July. The SDK for developers will be made available today.