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Windows 7 is the latest the most release version of operating systems produced by Microsoft for use on personal computers, including home and business desktops, laptops, netbooks, tablet PCs, and media center PCs.it uses Kernel type:Hybrid
Windows 7 introduced a large number of new features,
Presentations given by Microsoft is multi-touch support,
Redesigned Windows Shell with a new taskbar,the "Superbar"
Home networking system called HomeGroup,
Some applications of Microsoft Windows, including: Windows Calendar, Windows Mail, Windows Movie Maker, and Windows Photo Gallery, are not included in Windows 7 but are offered separately as part of the free Windows Live Essentials suite.
Windows 7 includes a number of new features,
* The new Action Center, which replaces Windows Security Center.When the action center detects a security threat, it displays a thumbnail with problems listed.
* such as advances in touch and handwriting recognition,
* virtual hard disks for support
* multi-core processors with improved performance,
* boot performance improved ,
* DirectAccess, and kernel improvements.
* Windows 7 adds support for systems using multiple heterogeneous graphics cards from different vendors (Heterogeneous Multi-adapter),
* New version of Windows Media Center, Gadget for Windows Media Center,
* the XPS Essentials Pack and Windows PowerShell also being included,
* Redesigned Calculator with multiline capabilities such as Programmer and Statistics modes along with unit conversion.
* Many new items have been added to the Control Panel,that including ClearType Text Tuner, Display Color Calibration Wizard, Gadgets, Recovery, Troubleshooting, Workspaces Center, Location and Other Sensors, Credential Manager, Biometric Devices, System Icons, and Display.
* Windows Security Center has been renamed to Windows Action Center, which has both security and maintenance of the computer.
* The default setting for User Account Control in Windows 7 has been criticized for allowing untrusted software to be launched with elevated privileges by exploiting a trusted application.
* Windows 7 can also supports Mac-like RAW image viewing through the addition of WIC-enabled image decoders, this enables raw image thumbnails, previewing and metadata display in Windows Explorer,and aslo a plus full-size viewing and slideshows in Windows Photo Viewer and Window Media Center
* Quick Launch toolbar has been replaced with pinning applications to the taskbar. Buttons for pinned applications are integrated with the task buttons. These buttons also enable the Jump Lists feature to allow easy access to common tasks.The revamped taskbar also allows the reordering of taskbar buttons. To the far right of the system clock is a small rectangular button that serves as the Show desktop icon. This button is part of the new feature in Windows 7 called Aero Peek. clicking over this button makes all visible windows transparent for a quick look at the desktop.
* Additionally, there is a feature named Aero Snap, that automatically maximizes a window when it is dragged to either the top or left/right edges of the screen.This also allows users to snap documents or files on either side of the screen to compare them. When a user moves windows that are maximized, the system restores their previous state automatically. This functionality is also accomplished with keyboard shortcuts.
* For developers, Windows 7 includes a new networking API with support for building SOAP-based web services in native code new features shorten application install times, reduced UAC prompts, simplified development of installation packages, and improved globalization support through a new Extended Linguistic Services API.
* Microsoft announced that color depths of 30-bit and 48-bit would be supported in Windows 7 along with the wide color gamut scRGB .
* The video modes in Windows 7 are 16-bit sRGB, 24-bit sRGB, 30-bit sRGB, 30-bit with extended color gamut sRGB, and 48-bit scRGB.
* Windows 7 also includes 13 additional sound schemes,
* It aslo allows multiple Windows environments, including Windows XP Mode, to run on the same machine, requiring the use of Intel VT-x or AMD-V. Windows XP Mode runs Windows XP in a virtual machine and redirects displayed applications running in Windows XP to the Windows 7 desktop.
* Furthermore Windows 7 supports the mounting of a virtual hard disk (VHD) as a normal data storage, and the bootloader delivered with Windows 7 can boot the Windows system from a VHD.
* The Remote Desktop Protocol (RDP) of Windows 7 is also enhanced to support real-time multimedia application including video playback and 3D games, thus allowing use of DirectX 10 in remote desktop environments.
Windows Vista OS was developed by Microsoft for use on personal computers, for example home and business desktops, laptops, tablet PCs, and media center PCs.Window Vista uses Kernel type :Hybrid.Windows Vista was known by its codename "Longhorn" .Microsoft's primary stated objective with Windows Vista has been to improve the state of security in the Windows operating system.
Windows Vista contains many changes and new features, including an updated graphical user interface visual style dubbed Windows Aero a redesigned search function multimedia tools including Windows DVD Maker redesigned networking, audio, print, display sub-systems.
Vista aims to increase the level of communication between machines on a home network, using peer-to-peer technology to simplify sharing files and digital media between computers and devices.
Windows Vista includes version 3.0 of the .NET Framework, allowing software developers to write applications without traditional Windows APIs.
Windows Vista revised and incorporated new features and functionalities not present in its predecessors, especially those from Windows XP.
Windows Explorer in Windows Vista
· Aero:is a new hardware-based graphical user interface is named Windows Aero, which is to be more cleaner and aesthetically pleasing than those of previous Windows versions, including new transparencies, live thumbnails, live icons, and animations, thus providing a new level of eye candy.
· Shell: is significantly different from Windows XP, offering a new range of organization, navigation, and search capabilities
· Instant seach, Windows Vista features a new way of searching called Instant Search, which is significantly faster and more in-depth (content-based) than the search features found in any of the previous versions of Windows.
· Sidebar,A transparent panel anchored to the side of the screen where a user can place Desktop Gadgets, which are small applets designed for a specialized purpose
· Explore7, New user interface, tabbed browsing, RSS, a search box, improved printing, Page Zoom, Quick Tabs, Anti-Phishing filter, a number of new security protection features, Internationalized Domain Name support (IDN), and improved web standards support.
· Windows Media Player 11, a major revamp of Microsoft's program for playing and organizing music and video. New features in this version include word wheeling (or "search as you type"), a new GUI for the media library, photo display and organization, the ability to share music libraries over a network with other Windows Vista machines, Xbox 360 integration, and support for other Media Center Extenders.
· Mail, A replacement for Outlook Express that includes a new mail store that improves stability, and features integrated Instant Search. It has the Phishing Filter like IE7 and Junk mail filtering that is enhanced through regular updates via Windows Update.
· Calander is a new calendar and task application.
· Photo Gallery, a photo and movie library management application. It can import from digital cameras, tag and rate individual items, adjust colors and exposure, create and display slideshows and burn slideshows to DVD.
· DVDs Maker, a companion program to Windows Movie Maker that provides the ability to create video DVDs based on a user's content. Users can design a DVD with title, menu, video, soundtrack, pan and zoom motion effects on pictures or slides.
· Media Centerwhich was previously exclusively bundled in a separate version of Windows XP, known as Windows XP Media Center Edition, has been incorporated into the Home Premium and Ultimate editions of Windows Vista.
· Games Explorer: Games included with Windows have been modified to showcase Vista's graphics capabilities. New games are Chess Titans, Mahjong Titans and Purble Place. A new Games Explorer special folder contains shortcuts and information to all games on the user's computer.
· Speech reconginationis integrated into Vista. It features a redesigned user interface and configurable command-and-control commands. Unlike the Office 2003 version, which works only in Office and WordPad, Speech Recognition in Windows Vista works for any accessible application. In addition, it currently supports several languages: British and American English, Spanish, French, German, Chinese (Traditional and Simplified) and Japanese.
The complete restructuring of the architecture of the audio, print, display, and networking subsystems; although the results of this work are visible to software developers, end-users will only see what appear to be evolutionary changes in the user interface.
Vista includes technologies such as
ReadyDrive which employ fast flash memory (located on USB drives and hybrid hard disk drives) to improve system performance by caching commonly used programs and data. This manifests itself in improved battery life on notebook computers as well, since a hybrid drive can be spun down when not in use.
The new technology called SuperFetch uses machine learning techniques to analyze usage patterns to allow Vista to make intelligent decisions about what content should be present in system memory at any given time. It uses almost all the extra RAM as disk cache. In conjunction with SuperFetch,
automatic built-in Windows Disk Defragmenter makes sure that applications are strategically positioned on the hard disk where they can be loaded into memory quickly
As part of the redesign of the networking architecture, IPv6 is fully incorporated into the OS and a number of performance improvements have been introduced, such as TCP window HYPERLINK "http://en.wikipedia.org/wiki/TCP_window_scale_option"scaling.
For graphics, Vista introduces a new Windows Display Driver Model and a major revision to Direct3D.
The new driver model facilitates the new Desktop Window Manager, which provides the tearing-free desktop and special effects that are the cornerstones of Windows Aero.
At the core of the OS many improvements have been made to the memory manager, process scheduler and I/O scheduler. The Heap Manager implements additional features such as integrity checking in order to improve robustness and defend against buffer overflow security exploits, A Kernel Transaction Manager has been implemented that enables applications to work with the file system and Registry using atomic transaction operations.
linux development is one of the examples of free and open source software collaboration; typically all the underlying source code can be used, freely modified, and redistributed, both commercially and non-commercially, by anyone under licenses such as the GNU General Public License.
Linux installed on a wide variety of computer hardware, ranging from embedded devices such as mobile phones and wristwatche. to mainframes and supercomputers.Linux is predominantly known for its use in servers;
Linux supports true preemptive multitasking (both in user mode and kernel mode), virtual memory, shared libraries, demand loading, shared copy-on-write executables, memory management, the Internet protocol suite, and threading.
Linux kernel map and bigger Interactive mapLinux is a monolithic kernel. Device drivers and kernel extensions run in kernel space, with full access to the hardware, although some exceptions run in user space. The graphics system most people use with Linux doesn't run in the kernel,
Kernel mode preemption allows device drivers to be preempted under certain conditions. This feature was added to handle hardware interrupts correctly and improve support for symmetric multiprocessing (SMP). Preemption also improves latency, increasing responsiveness and making Linux more suitable for real-time applications.
In Linux, a "panic" is an unrecoverable system error detected by the kernel as opposed to similar errors detected by user space code. It is possible for kernel code to indicate such a condition by calling the panic function located in the header file sys/system.h. However, most panics are the result of unhandled processor exceptions in kernel code, such as references to invalid memory addresses. These are typically indicative of a bug somewhere in the call chain leading to the panic. They can also indicate a failure of hardware, such as a failed RAM cell or errors in arithmetic functions in the processor caused by a processor bug, overheating/damaged processor, or a soft error.
Linux is a monolithic kernel rather than a microkernel .The debate started in 1992 about Linux and kernel architecture in general on the Usenet. Unlike traditional monolithic kernels, device drivers are easily configured as Loadable Kernel Modules, and loaded or unloaded while running the system.
Linux version of the C programming language supported by number of short sections of code written in the of the target architecture. Intel claimed to have modified the kernel so that its C compiler also was capable of Many other languages are used in some way, primarily in connection with the kernel build process These include Perl, Python, and various shell scripting languages. Some drivers may also be written in C++, Fortran, or other languages, but this is strongly discouraged. Linux's build system only officially supports GCC as a kernel and driver compiler.
While not originally designed to be portable, Linux is now one of the most widely ported operating system kernels, running on a diverse range of systems from the iPAQ , IBM System z9. Linux runs as the main operating system on IBM's Blue Gene supercomputers. Also, Linux has been ported to various handheld devices such as TuxPhone and Apple's iPod. The Android operating system, developed for mobile phone devices, uses the Linux kernel.
Virtual machine architectures
The Linux kernel has extensive support for and runs on many virtual machine architectures both as the host operating system and as a client operating system. The virtual machines usually emulate Intel x86 family of processors, though in a few cases PowerPC or AMD processors are also emulaed.
Mac OS X Tiger
Mac OS X Tiger v10.4 is the fifth major release of Mac OS X,uses kernel Apple's desktop and server operating system for Macintosh computers. Tiger is also the first version of any released Apple operating system to work on Apple-Intel architecture machines (Apple machines using x86 processors).Tiger the longest running version of Mac OS X which was included with all new Macintosh computers.
Apple advertises that Tiger has 200+ features, including:
* Spotlight - Spotlight is a full-text and metadata search engine, which can search everything from Word documents to iCal calendars to Address Book cards, as well as any text within PDF files.
* iChat AV - The new iChat AV 3.0 in Tiger can supports up to four participants in a video conference and ten participants in an audio conference. It also now supports communication using the XMPP protocol. A XMPP server called iChat Server is included on Mac OS X Tiger Server.
* Safari RSS - The new Safari 2.0 web browser in Tiger features a built-in reader for RSS and Atom web syndication that can be accessed easily from an RSS button in the address bar of the web browser window.
* Mail 2 - The new version of Mail.app email client included in Tiger featured an updated interface, "Smart Mailboxes" which utilize the Spotlight search system, parental controls, as well as several other features.
* Dictionary/Thesaurus based on the New Oxford American Dictionary, Second Edition, accessible through an application, Dictionary, a Dashboard widget, and as a system-wide command .
* .Mac syncing - in Tiger are now accomplished through the .Mac system preferences pane rather than the iSync application.
* QuickTime 7 - A new version of Apple's multimedia software has support for the new H.264/AVC codec which offers better quality and scalability than other video codecs. .
* Xcode 2.0 - Xcode 2.0, Apple's Cocoa development tool now includes visual modelling, an integrated Apple Reference Library and graphical remote debugging.
* Automator - Automator uses workflows to process repetitive tasks automatically
* Grapher - Grapher is a new application capable of creating 2D and 3D graphs similar to that of Graphing Calculator.
* Quartz Composer - is a development tool for processing and rendering graphical data.
· AU Lab - AU Lab is a developer application for testing and mixing Audio Units.
* An upgraded kernel which optimized kernel resource locking and access control lists, and with support for 64-bit userland address spaces on machines with 64-bit processors.
* An updated libSystem with both 32-bit and 64-bit versions; with the kernel change, this allows individual applications to address more than 4GB of memory when run on 64-bit processors.
* A new startup daemon called launchd that allows for faster boots.
* A new graphics processing API, Core Image, leveraging the power of the available accelerated graphics cards.
* Core Image allows programmers to easily leverage programmable GPUs for fast image processing for special effects and image correction tools.for example Image Units included are Blur, Color Blending, Generator Filters, Distortion Filters, Geometry Filters, Halftone features and much more.
* A new video graphics API, Core Video, which leverages Core Image to provide real-time video processing.
Core Audio integrates a range of audio functionality directly into the operating system.
The Apple TV, was ships with a customized version of Mac OS X v10.4 branded "Apple TV OS" that replaces the usual graphical user interface with an updated version of Front Row.
Mac OS X Snow Leopard
Mac OS X Snow Leopard v 10.6 is the seventh release of Mac OS X, Apple's desktop and server Unix-based operating system.
This version of Mac OS X focuses on improving performance, efficiency and reducing its overall memory footprint , rather than new end-user features. This is also the first Mac OS release since the introduction of System 7.1.2 that does not support the PowerPC architecture, as Apple now intends to focus on its current line of Intel-based products.
"Leopard", the company has acknowledged that there is no technical barrier preventing a direct upgrade from Mac OS X v10.4 "Tiger". The recommended upgrade path for OS X "Tiger" is through the current release of the "Mac Box Set", which includes OS X Snow Leopard, iLife '09, and iWork '09.
Snow Leopard does not support PowerPC-based Macs (e.g., Power Macs, PowerBooks, iBooks, iMacs (G3-G5), all eMacs, although PowerPC applications are supported via Rosetta, which is now an optional install.
* Boot Camp now allows Windows partitions to read and copy files from HFS+ partitions. The new version also adds support for advanced features on Cinema Displays and a new command-line version of the Startup Disk Control Panel.
* The Finder has been completely rewritten in 64-bit Cocoa to take advantage of the new technologies introduced in Snow Leopard. This has resulted in a much smaller OS footprint, taking up about 7 GB less space than Mac OS X v10.5. iChat enhancements include greater resolution video chats in iChat Theater and lowered upload bandwidth requirements.
* Microsoft Exchange support is now integrated into the Mail, Address Book, and iCal applications. However, only Microsoft Exchange 2007 is supported and customers using prior versions of Exchange must either upgrade or use Microsoft Entourage.
* Full Multi-touch support has been added to notebooks prior to those introduced in October 2008.While the original MacBook Air and other early multi-touch enabled notebooks had support for some gestures, they were unable to use four-finger gestures. This limitation has now been removed in Snow Leopard.
* Preview now has artificial intelligence algorithms that allow it to infer the structure of a paragraph in a PDF document.
* QuickTime X, the next version of QuickTime player and multimedia framework, has been completely rewritten into a full 64-bit Cocoa application and builds on the media technologies in Mac OS X, such as Core Audio, Core Video, and Core Animation, to deliver playback. QuickTime X also supports HTTP live streaming and takes advantage of ColorSync to provide high-quality color reproduction. If Snow Leopard is installed on a Mac with an nVidia GeForce 9400M graphics card, QuickTime X will be able to use its video-decoding capabilities to reduce CPU load.
* Safari 4 features Top Sites, Cover Flow, VoiceOver, expanded standards support, and built-in crash resistance, which prevents browser crashes caused by plug-ins by running them in separate processes. Safari 4 is not new to Snow Leopard, as it is available for free in Mac OS X 10.4 (Tiger) and 10.5 (Leopard).
* Time Machine connection establishment and backups are now much faster.
* Putting aside these important but long-term changes, here are Snow Leopard's most immediately beneficial new features and enhancements.
* ActiveSync Following in the footsteps of the iPhone, Snow Leopard makes these Microsoft technologies native to the OS.This giving users the same capabilities as with the better-designed, less-memory-intensive apps -- Mail, iCal, and Address Book -- included in OS X.
* Exposé integration in the Dock The Mac OS X Dock makes it easy to access applications, open documents, and common folders.Open documents are even more easily accessed in Snow Leopard, thanks to the integration of Exposé. click and hold an app icon in the Dock, you get preview windows for each of its open documents, allowing you to switch easily among them or to close them, all without having to clutter your screen with document windows.
* Automatic location detection Snow Leopard changes the time zone for you automatically (if you set that as the default behavior), using Wi-Fi mapping to figure out where you are -- you will need to be connected to a Wi-Fi access point or router. iCal can also be set to adjust the times to the current time zone automatically, so your calendar always reflects the current times.
* The new Preview now can open multiple PDF documents, display their contents as contact sheets, and show thumbnails of pages in a sidebar for easy navigation. In other words, it works a lot like Adobe Reader. That's one fewer app to launch -- and since Preview loads much faster than Reader, you can get PDFs' contents much faster now.
* Movie and screencast recording Snow Leopard takes the formerly QuickTime Pro and makes it a standard, free app in Mac OS X. That means you can record movies and -- great for many marketing, education, and Web professionals -- screencasts from your Mac with no additional software.
* Systemwide automatic text replacement Snow Leopard lets you specify such substitutions via the Keyboard system preference, so you have a common set of substitutions available to all applications. Right now, only TextEdit, Mail, and various Apple apps use this common auto-text service, but if other software developers adopt it, you may finally get all your text-oriented apps to autocorrect the same way.
* No more gesture segregation Snow Leopard fixes that, so gesture-capable trackpads now support all gestures, no matter what Mac model you have. (Of course, your Mac has to have a gesture-capable trackpad, so models before 2006 aren't helped out by this update.)
Mac OS X Tiger added limited support for 64-bit applications on machines with 64-bit processors; Leopard extended the support for 64-bit applications to include applications using most of Mac OS X's libraries and frameworks.
In addition, the Mac OS X kernel has been rebuilt to run in 64-bit mode on some machines. On those machines, Snow Leopard supports up to 16 terabytes of RAM. Newer Xserve and Mac Pro machines will run a 64-bit kernel by default; newer iMac machines can run a 64-bit kernel, but will not do so by default. Users wishing to use the 64-bit kernel on those machines must hold down the numbers 6 and 4 on the keyboard while booting to get the 64-bit kernel to load. A change to the com.apple.Boot.plist will also enable users with compatible computers to permanently boot into 64-bit for those wishing to do so.
An anti-malware feature was added to the system that alerts the user if malware is detected.
Despite the lack of ASLR, Apple has strengthened OS X by implementing stack protection, and sandboxing more OS X components such as the H.264 decoder in QuickTime and browser plug-ins as a separate process in Safari.