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The first commercial version, Android 1.0, was released in September 2008. ... codename and released in alphabetical order, beginning with Android 1.5 ... the first CUPKAKE
mascot logos, but the current green Android logo was designed by Irina Blok. Android
Cupkake
1.5

Donut:

Android 1.6

Eclair:

Android 2.0
Android 2.1

Froyo: (short for "frozen yogurt")

Android 2.2

Gingerbread:

Android 2.3

Honeycomb:

Android 3.0
Android 3.1
Android 3.2

Ice Cream Sandwich:

Android 4.0

Jelly Bean:

Android 4.1
Android 4.2
Android 4.3

Write Advantages of Open-Source?

Advantages of Open-Source
Linux was one of the first open-source technologies, but many programmers have contributed and added software that’s completely open-source for any user. This means that you can download the source code and change it any way you like. Some developers have restrictions on how you can distribute the code. For instance, some developers allow you to change the code, but you cannot distribute it for money.
One main advantage of open-source technologies such as Linux is the wide range of options available to users and the increased security. With Linux being open-source, several distributions are available to the end-user.Debian, Fedora, Ubuntu and Mint are just a few of the distributions available to end users, and these distributions are completely free to download.

Security is the other main advantage. Several white hat hackers have contributed to the overall security of Linux, and by making the source available to anyone, security experts can help identify any main security flaws in the operating system. The advantage over operating systems such as Windows is that security flaws are caught before they become an issue for the public.

Advantages of Unix?

Advantages

· Full multitasking with protected memory. Multiple users can run multiple programs each at the same time without interfering with each other or crashing the system.

· Very efficient virtual memory, so many programs can run with a modest amount of physical memory.

· Access controls and security. All users must be authenticated by a valid account and password to use the system at all. All files are owned by particular accounts. The owner can decide whether others have read or write access to his files.

· A rich set of small commands and utilities that do specific tasks well -- not cluttered up with lots of special options. Unix is a well-stocked toolbox, not a giant do-it-all Swiss Army Knife.

· Ability to string commands and utilities together in unlimited ways to accomplish more complicated tasks -- not limited to preconfigured combinations or menus, as in personal computer systems.

· A powerfully unified file system. Everything is a file: data, programs, and all physical devices. Entire file system appears as a single large tree of nested directories; regardless of how many different physical devices (disks) are included.

· A lean kernel that does the basics for you but doesn't get in the way when you try to do the unusual.

· Available on a wide variety of machines - the most truly portable operating system.

Why we use UNIX?

It is impossible for non-Microsoft programmers to see the code, and so errors can only be spotted and fixed by Microsoft engineers. This is a very much smaller group than the number of people working on the open-source UNIX systems.

1: UNIX has been designed and built by a community of computer scientists, mathematicians and engineers with the goal of producing a robust, secure and transparent operating system. There are no artificial deadlines or shipping dates, so new code can be released as soon as it has been written, then tested to exhaustion by thousands of other programmers and users. And that code is constantly being improved by people with interests in the highest quality software possible.

2: The development of Microsoft Windows has been driven by the marketing department with the goal of maximizing market share and profit for the company. Shipping dates are compressed, leading to commercial releases which are not production-ready. The source code is not publicly available, so it cannot be tested and repaired by interested people who are not employed by Microsoft. As long as the company can continue to move product, they don't care about quality.

3: This is the primary reason why Microsoft computers fail so often, and need to be rebooted practically every day. UNIX servers, on the other hand, often run without reboot for months or years.

4: UNIX programmers are interested in quality and technical excellence. They share their ideas so that the system can be continually improved. Microsoft is interested in profit. They have a history of making decisions that benefit their market position at the expense of quality software, and to the clear detriment of their customers.

Which OS is used in mobiles?

1. Android OS (Google Inc.)

The Android mobile operating system is Google's open and free software stack that includes an operating system, middleware and also key applications for use on mobile devices, including smartphones. Updates for the open source Android mobile operating system have been developed under “dessert-inspired” code names (Cupcake, Donut, Eclair, Gingerbread, Honeycomb, Ice Cream Sandwich) with each new version arriving in alphabetical order with new enhancements and improvements.

2. Bada (Samsung Electronics)

Bada is a proprietary Samsung mobile OS that was first launched in 2010. The Samsung Wave was the first smartphone to use this mobile OS. Bada provides mobile features such as multipoint-touch, 3D graphics and of course, application downloads and installation.

3. BlackBerry OS (Research in Motion)

The BlackBerry OS is a proprietary mobile operating system developed by Research In Motion for use on the company’s popular BlackBerry handheld devices. The BlackBerry platform is popular with corporate users as it offers synchronization with Microsoft Exchange, Lotus Domino, Novell GroupWise email and other business software, when used with the BlackBerry Enterprise Server.

4. IPhone OS / IOS (Apple)

Apple's iPhone OS was originally developed for use on its IPhone devices. Now, the mobile operating system is referred to as IOS and is supported on a number of Apple devices including the iPhone, I Pad, I Pad 2 and iPod Touch. The IOS mobile operating system is available only on Apple's own manufactured devices as the company does not license the OS for third-party hardware. Apple IOS is derived from Apple's Mac OS X operating system.

5. MeeGo OS (Nokia and Intel)

A joint open source mobile operating system which is the result of merging two products based on open source technologies: Maemo (Nokia) and Moblin (Intel). Mee Go is a mobile OS designed to work on a number of devices including smartphones, netbooks, tablets, in-vehicle information systems and various devices using Intel Atom and ARMv7 architectures.

6. Palm OS (Garnet OS)

The Palm OS is a proprietary mobile operating system (PDA operating system) that was originally released in 1996 on the Pilot 1000 handheld. Newer versions of the Palm OS have added support for expansion ports, new processors, external memory cards, improved security and support for ARM processors and smartphones. Palm OS 5 was extended to provide support for a broad range of screen resolutions, wireless connections and enhanced multimedia capabilities and is called Garnet OS.

7. Symbian OS (Nokia)

Symbian is a mobile operating system (OS) targeted at mobile phones that offers a high-level of integration with communication and personal information management (PIM) functionality. Symbian OS combines middle ware with. wireless communications through an integrated mailbox and the integration of Java and PIM functionality (agenda and contacts). Nokia has made the Symbian platform available under an alternative, open and direct model, to work with some OEMs and the small community of platform development collaborators. Nokia does not maintain Symbian as an open source development project.

8. Web OS (Palm/HP)

Web OS is a mobile operating system that runs on the Linux kernel. Web OS was initially developed by Palm as the successor to its Palm OS mobile operating system. It is a proprietary Mobile OS which was eventually acquired by HP and now referred to as web OS (lower-case w) in HP literature. HP uses web OS in a number of devices including several smartphones and HP Touch Pads. HP has pushed its web OS into the enterprise mobile market by focusing on improving security features and management with the release of web OS 3.x. HP has also announced plans for a version of web OS to run within the Microsoft Windows operating system and to be installed on all HP desktop and notebook computers in 2012.

9. Windows Mobile (Windows Phone 7)

Windows Mobile is Microsoft's mobile operating system used in smartphones and mobile devices – with or without touchscreens. The Mobile OS is based on the Windows CE 5.2 kernel. In 2010 Microsoft announced a new smartphone platform called Windows Phone 7.

Write qualities to buy a laptop?

1. Size: If portability is your main concern, then you need to consider a notebook that has a small-ish screen and a light weight. Any laptop marketed as an Ultrabook should fit your bill here, as they are designed to be slim and light. More to the point, though, look for a laptop with a screen that’s 12.5-13.3 inches in size, and a weight that is from 1-1.5kg.

2. Screen quality: You’ll be staring at your laptop for many hours every day, so you want to make sure you get a screen that is comfortable to look at. Many laptops these days also have touchscreens, which means they are glossy. Glossy screens lead to reflections, so consider a laptop that doesn’t have a touchscreen.

Next, look at the resolution. A 1920x1080-pixel resolution (aka Full HD) should be considered if you want plenty of space to line up windows and keep things in view. Finally, the viewing angles are extremely important. A laptop screen that touts IPS (in-plane switching) technology offers the widest viewing angles and the best user comfort.

Try not to buy blind. If possible, go into a store and see the screen for yourself. Otherwise, rely on multiple reviews to get a good overview of the product.

3. Keyboard quality: For long typing sessions, you must get a laptop that has a comfortable keyboard. You don’t want to get a keyboard that packs in every key under the sun (think keyboards that have squished in number pads) because that can translate to a poor overall user experience when hunting for keys like the arrows.

You want a keyboard that has a comfortable layout with full-sized keys and some space around the arrow keys. The keys should have adequate travel on the downstroke and snappy responsiveness when you let them go. Make sure the keyboard is also backlit, so that you can type with an easier view on the keys in dimly lit environments.