1. Introduction to Android

Why Android ?

• Android has >50% of the smartphone market. Blackberry, windows mobile are rapidly losing market share since their platforms not nearly as interesting to develop for as android/iPhone.
• Android is the fastest growing smartphone platform. Open source & works on multiple platforms (no need to own a Mac).
• Easy to learn for Java(& C++) programmers. Much easier to transition to than objective-C.

What is Android ?

Android is an open software platform for mobile development. It is a complete stack that includes from operating system through middleware and up through applications:

1. A variant of the Linux OS optimized for power conservation & local IPC.

2. An optimized Java Virtual Machine(Dalvik), a subset of Java libraries running on Dalvik, native C/C++ libraries & a hardware abstraction layer.

3. Middleware, including GUIs, telephony services, camera, multimedia, app frameworks, app distribution etc.

4. Then there are common set of apps provided by different vendors along with phone.

Open Handset Alliance (OHA)

• It is a group of 80+ companies that covers the entire area for mobile devices. 
• There are software companies that are focused on application development. 
• Then there are commercialization companies like Accenture, Wipro, L&T infotech etc.. that support the platform through a professional services model 
• Various mobile operators are there like vodafone, Sprint, docomo etc..
• Handset manufacturers like HTC, Samsung, Sony and others who are manufacturers for android devices are also part of OHA.
• Lastly there are semiconductor companies that supply the chips for these.

So all of them have grouped together and formed this OHA under which they support the android platform.

Android Platform Versions

After android beta version (Nov 2007), first commercial version, Android 1.0 was released in 2008.

Since then, all versions were developed under a themed code name and released in alphabetical order:

• Cupcake (1.5)
• Doughnut (1.6)
• Eclair (2.0–2.1)
• Froyo (2.2–2.2.3)
• Gingerbread (2.3–2.3.7)
• Honeycomb (3.0–3.2.6)
• Ice Cream Sandwich (4.0–4.0.4)
• Jelly Bean (4.1–4.3.1)
• KitKat (4.4–4.4.4)