History Of Linux

The History of Linux began in 1991 with the commencement of a personal project by a Finnish student, Linus Torvalds, to create a new operating system kernel.

Since then, the resulting Linux kernel has been marked by constant growth throughout its history. Since the initial release of its source code in 1991, it has grown from a small number of C files under a license prohibiting commercial distribution to its state in 2009 of over 370 megabytes of source under the GNU General Public License.
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Events leading to creation
Ken Thompson and Dennis Ritchie

The Unix operating system was conceived and implemented by Ken Thompson and Dennis Ritchie (both of AT&T Bell Laboratories) in 1969 and first released in 1970. Its availability and portability caused it to be widely adopted, copied and modified by academic institutions and businesses. Its design became influential to authors of other systems.[citation needed]

In 1983, Richard Stallman started the GNU project with the goal of creating a free UNIX-like operating system. As part of this work, he wrote the GNU General Public License (GPL). By the early 1990s there was almost enough available software to create a full operating system. However, the GNU kernel, called Hurd, failed to attract enough attention from developers leaving GNU incomplete.

Another free operating system project, initially released in 1977, was the Berkeley Software Distribution (BSD). This was developed by UC Berkeley from the 6th edition of Unix from AT&T. Since BSD contained Unix code that AT&T owned, AT&T filed a lawsuit (USL v. BSDi) in the early 1990s against the University of California. This strongly limited the development and adoption of BSD.

In 1985, Intel released the 80386, the first x86 microprocessor with 32-bit instruction set and MMU with paging.

In 1986, Maurice J. Bach, of AT&T Bell Labs, published The Design of the UNIX Operating System. This definitive description principally covered the System V Release 2 kernel, with some new features from Release 3 and BSD.

MINIX, a Unix-like system intended for academic use, was released by Andrew S. Tanenbaum in 1987. While source code for the system was available, modification and redistribution were restricted. In addition, MINIX's 16-bit design was not well adapted to the 32-bit features of the increasingly cheap and popular Intel 386 architecture for personal computers.

These factors and the lack of a widely adopted, free kernel provided the impetus for Torvalds's starting his project. He has stated that if either the GNU or 386BSD kernels were available at the time, he likely would not have written his own.

Resources : http://en.wikipedia.org/wiki/History_of_Linux

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About Windows 8

Development of this operating system started before the release of its predecessor in 2009. Its existence was first announced in January 2011 at Consumer Electronics Show. During its development and test phases,
 Microsoft released three pre-release versions: Developer Preview (September 13, 2011), Consumer Preview (February 29, 2012), and Release Preview (May 31, 2012). On August 1, 2012, Windows 8 graduated from the development stage and was released to manufacturing. Windows 8 is slated for general availability on October 26, 2012.[2]

Windows 8 introduces significant changes to the operating system's graphical user interface and platform, such as a new interface design incorporating a new design language used by other Microsoft products, a new Start screen to replace the Start menu used by previous versions of Windows, a new online store that can be used to obtain new applications, along with a new platform for apps that can provide what developers described as a "fast and fluid" experience with emphasis on touchscreen input.[3] Additional security features were also added to the operating system, such as a built-in antivirus program and a secure boot feature on systems with UEFI firmware. Secure boot requires the operating system to be digitally signed to protect malware from infecting the boot process. The implementation of this feature has sparked controversy among supporters of free software. Windows 8 also introduces an edition of the operating system designed to run on devices that utilize the ARM architecture, known as Windows RT.


 Features new to Windows 8

Desktop and shell

Windows 8 employs a new user interface based on Microsoft's Metro design language. The environment features a new tile-based Start screen similar to that of the Windows Phone operating system, which has replaced the previous Start menu entirely. The Start screen displays a customizable array of tiles linking to various apps and desktop programs, some of which can display constantly updated information and content through "live tiles".[3] As a form of multi-tasking, apps can also be snapped to the side of a screen.[3]

A vertical toolbar known as the charms bar (accessed by swiping from the right edge of a touchscreen, or pointing the cursor at hotspots in the right corners of a screen) provide access to system and app-related functions, such as search, sharing, device management, settings, and a Start button. The traditional desktop environment for running desktop applications is accessed via a tile on the new Start screen. The Start button from previous versions of Windows has been removed from the taskbar in favor of a hotspot in the bottom-left corner (but can still also be activated via a button on the device if applicable, or on the charms bar).[30][31]

Apps and the desktop can be switched between by either swiping from the left edge of a touchscreen, clicking in the top-left corner of the screen, using Alt+Tab, or by pointing in the top-left corner and moving the cursor down to reveal a thumbnail list of active apps.[31]
Apps
A music app for Windows 8, shown snapped like a sidebar to the Windows Desktop

Windows 8 introduces a new style of application, Windows Store apps; Microsoft developer Jensen Harris intends these apps to provide a "fast and fluid" experience; referring to their optimization for touchscreen environments and their smaller scope in relation to desktop applications. Apps can run either in a full-screen mode, or be docked directly to the side of a screen.[3] They can also provide notifications and a "live tile" on the Start screen for dynamic content. Apps can also use "contracts"; a collection of hooks to provide common functionality that can integrate with other apps, such as search and sharing.[3] These apps are primarily distributed and updated through its namesake Windows Store, a new distribution platform.[32][33]

The apps run within a new set of APIs known as the Windows Runtime (WinRT), which supports programming languages such as C, C++, VB.NET, C#, along with HTML5 and JavaScript.[3] Apps written for WinRT are also cross-compatible with both Intel-compatible and ARM versions of Windows.[33]

To ensure stability and security, they run within a sandboxed environment, and require permissions to access certain functionality, such as accessing the Internet or a camera.[32] Retail versions of Windows 8 will only be able to install these apps through the Windows Store; the enterprise version will allow system administrators to deploy internally-developed apps.[34][32]

Windows Store apps were originally known as "Metro-style apps" during the development of Windows 8. The term was reportedly phased out in August 2012; a Microsoft spokesperson denied rumors that the change was related to a potential trademark issue, and stated that "Metro" was only a codename that would be phased out prior to Windows 8's release.[35] Following these reports, the terms "Modern UI-style apps",[36] "Windows 8-style apps"[37] and "Windows Store apps" began to be used to refer to the new apps. On September 12, 2012, Soma Somasegar (vice president of Microsoft's development software division) officially confirmed in an interview that they would be known as "Windows Store apps".[38]



Resources : http://en.wikipedia.org/wiki/Windows_8

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