Difference Between Windows XP Versus Linux

Trying to compare Windows XP versus Linux is difficult for several reasons, including
• Windows XP requires a relatively recent computer with at least 128MB of RAM to function, while Linux can run successfully on even 486-based systems long obsolete for use with Windows
• Windows XP is available in just two versions (Home Edition and Professional), while Linux is available in numerous distributions
• Windows XP is primarily a GUI-based operating system, while Linux is primarily command-line driven (although KDE and Gnome, the two most common GUIs, are increasingly popular)
Although Linux has made great strides in so-called "back end" uses such as Web servers, network servers, and embedded devices, Windows XP is a better choice for desktops for several reasons, including
• Journaling file system for higher reliability and crash recovery.
• Compatibility testing and guarantees for operating system and applications.
• Wide availability of commercial applications at retail and online stores.
• Clustering and base-load balancing.
• Long-term roadmap of operating system deployment plans.
• Larger hard disks and maximum file sizes. Linux's maximum file size is 2 Gigabytes; Windows XP's limit is 18.4 quintillion bytes (Petabytes).
• "Synchronous I/O," which allows smoother running in Windows XP when multiple threads are being processed and waiting for input or output. It improves SMP scalability as well.
• Consistent GUI across all toolsLinux has no single standard GUI at present.
• A single version which can be installed for most major languages and countries.
• Dedicated support network, with close to one-half million Microsoft-certified trained professionals and engineers.
We believe that the entire Linux/Windows controversy comes down to this: Microsoft offers lots and lots of powerful stuff (which you can use to build very sophisticated software) from the C++ compiler, to the component-nature of Excel and other apps, to the ASP scripting language, COM, and so on. These tools let you leverage everything Microsoft offers to make very powerful applications. As people used to say in the '60s and '70s, nobody ever lost his job buying IBM. Now it's safe to say nobody ever lost his job buying Microsoft. True, you're locked into Windows because the stuff you build on Windows systems can't be ported to UNIX variants, but that's the price you pay for the tools, the user base, and the support and training. Although increasing support options are available for Linux (see www.linuxcare.com), enterprise-level support for Linux is still not as widespread as for Windows.

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Windows XP Professional Compare to UNIX and Linux

Windows XP's kernel, like Windows 2000's, has its roots in UNIX. UNIX is a very popular multitasking operating system developed at Bell Labs in the early 1970s. It was designed by programmers for programmers. In fact, the language C was developed just to write UNIX. Even though UNIX has become a friendlier operating system with the addition of Windows-like interfaces such as MOTIF, it's still relatively user-unfriendly, requiring cryptic commands much like DOS.

UNIX

Because it is written in C, UNIX can run on any computer that has a C compiler, making it quite portable. AT&T gave away the UNIX source code to universities and licensed it to several companies during its early years. AT&T no longer owns UNIX; the UNIX trademark is now owned by OpenGroup, though the source code is claimed to be owned by the Santa Cruz Operation (SCO), though this is now in debate.

Unfortunately, to avoid even the licensing fees to AT&T, UNIX lookalikes sprung up over the years. Without the proper license, these versions could not call themselves UNIX, only UNIX-like. And as these clones proliferated, cross-compatibility became an issue. More than a handful of versions (dialects) of UNIX have appeared, the primary contenders being AT&T's own, known as System V, and another developed at the University of California at Berkeley, known as BSD4.x, x being a number from 1 to 3. Other popular brands of UNIX these days are HP-UX from HP, AIX from IBM, Solaris from Sun, and SCO's version, UnixWare.

In 1984, industry experts were brought together to create guidelines and standards for UNIX clones, in hopes of creating a more coherent market. The result was a single UNIX specification, which includes a requirement for POSIX (Portable Operating System Interface for UNIX) compliance. Accepted by the IEEE and ISO, POSIX is a standard that makes porting applications and other code between variants of UNIX as simple as recompiling the source code.

NOTE

Another popular version of UNIX that runs on the PC platform is called FreeBSD. Briefly, FreeBSD 4.x is a UNIX-like operating system based on U.C. Berkeley's 4.4BSD-lite release for the Intel 386 platform. It is also based indirectly on William Jolitz's port of U.C. Berkeley's Net/2 to the Intel 386, known as 386BSD, though very little of the 386BSD code remains. You can find a fuller description of what FreeBSD is and how it can work for you at www.freebsd.com.

UNIX has been the predominant operating system for workstations connected to servers, mostly because of its multiuser capabilities and its rock-solid performance. Windows NT and its successors, Windows 2000 and Windows XP, have been making inroads due to the extensive number of development tools and applications for the Windows platform. However, the low-cost UNIX variant called Linux is revitalizing UNIX across all platforms.

Linux

Linux is a UNIX lookalike. Linux isn't a port of a preexisting operating system, but rather it was written from the ground up by Linus Torvalds, a Finnish-born computer scientist who wanted to develop a UNIX-like operating system for computer students to run on low-cost Intel computers. Torvalds wrote the kernel with the help of a handful of computer programmers. Like all variants of UNIX, Linux has many of the features of NT/Windows 2000/Windows XP, such as true multitasking, virtual memory, shared libraries, intelligent memory management, and TCP/IP networking.

Linux is an open system, and programmers worldwide are invited to participate in its building and refinement. Unlike other flavors of UNIX that were based on licensed source code, Linux is based on Minix, which mimics UNIX in a way that does not infringe on the UNIX license. That's why Linux distributions are practically free.

NOTE

Actually, the term Linux pertains only to the kernel. What people have come to refer to as Linux is actually a collection of separate pieces of code, the majority of which are GNU. It was not until Linux came together with GNU that the full power of the Linux OS (what GNU enthusiasts would called GNU Linux) crystallized.

The several popularly distributed Linux versions are differentiated mostly by the selection of tools and utilities bundled with them. The most popular package at this point is Red Hat Linux. If you want to go it alone, you can acquire Linux for free, but buying some commercially bundled packages makes the job of installation and support easier because you get support. Technically, the distribution of the software must be free, in accordance with the GNU General Public License (GPL) agreement governing the distribution of Linux and the collected modules that accompany it.

Linux is now running on a wide variety of systems, including Sun JavaStations, the IBM RS/6000, and the Alpha chip originally developed by DEC and later sold by Compaq, MIPS, SPARC, Open VMS, Digital UNIX, and other platforms.

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Differences Between Windows XP Home Edition, Windows XP Professional, 64-Bit, and Server Versions of Windows XP

Windows XP comes in two distinct varieties for 32-bit processors:
• Home Edition
• Professional
Although both versions contain the same integrated applications and multimedia features, Windows XP Professional also includes corporate network support, backup, and security features similar to those found in Windows 2000 Professional.
The now-available 64-bit CPUs such as Intel Itanium and AMD's Athlon 64 and Opteron can run advanced versions of XP designed to take advantage of their speed and other enhancements. Windows XP 64-bit Edition is the Intel-based workstation version. It supports up to 16GB of physical RAM and up to 16 terabytes (16TB) of virtual memory, and takes full advantage of the superior floating-point performance of the Itanium processor. One or two Itanium processors can be used. Windows XP 64-bit Edition runs 32-bit Windows programs in a subsystem. The user interface is very similar to Windows XP Professional but the features will vary. Another 64-bit version has been developed for the AMD Athlon 64 and Opteron chips, dubbed "Windows XP 64-Bit Edition for 64-Bit Extended Systems."
Both 64-bit versions use an emulation layer called WOW64 to run Win32-based applications. When running on the Intel 64-bit processor, complaints are that the 32-bit programs run a bit too slowly. Early testing indicates that the AMDs run 32-bit applications considerably faster than the Itaniums do. 64-bit versions are supplied preinstalled on computer hardware.
Both 64-bit versions use an emulation layer called WOW64 to run Win32-based applications, although for best performance, Microsoft recommends using 32-bit software on 32-bit Windows systems. The emulation feature allows organizations to use their Itanium-based systems with existing Windows applications until 64-bit versions are created internally or purchased from software vendors.
What about 32-bit server versions of Windows XP? Microsoft has multiple server editions of Windows XP, generally dubbed Microsoft Windows 2003 Server. The editions differ based on variations in the total amount of memory used by each version, the number of processors supported, and the number of domains that can be controlled. As of this writing, I counted 16 specialized servers for areas such as storage servers, SQL servers, speech servers, commerce servers, and so on.
Table 1 Compares Windows XP Home Edition and Windows XP Professional to other versions of Windows.
Table 1 Various Capabilities of Windows XP Home Edition as Compared to Earlier Versions of Windows

Fig. 1: Differences between windows XP

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Security-relevant Standards Organizations

Organization Description

ABA


The American Bankers Association develops computer standards for financial and banking areas. The ABA is the Secretariat for X9, ANSI's Accredited Standards Committee for Financial Services. Standards developed by this committee focus on encryption and message authentication for financial institutions. The ABA also develops standards for personal identification numbers (PINs) and key management.

ANSI


The American National Standards Institute is the officially designated national standards organization in the United States and is the formal U.S. representative to ISO. ANSI does not develop its own standards, but is the clearinghouse for U.S. and international standards-for example, ASCII code, languages (e.g., C and FORTRAN), and communications protocols. ANSI committee are working on such security concerns as encryption and message authentication.

CBEMA


The Computer and Business Equipment Manufacturers Association develops standards in a variety of areas, including languages, graphics, and database technologies, and submits these standards to ANSI for approval as ANSI standards. CBEMA is the Secretariat for X3, ANSI's Accredited Standards Committee for Information Processing.

CCITT


The Comité Consultatif Internationale Telegraphique et Telephonique (International Telegraph and Telephone Consultative Committee) was established under the United Nations. It is responsible for the X.25 (packet-switched networks) and X.400 (electronic mail) standards and for other international communications standards. CCITT works with ISO on international standards for security.

ECMA


The European Computer Manufacturers Association is an association of approximately 50 European computer manufacturers. Its security groups are involved in developing standards for security in such areas as distributed interactive processing, distributed office applications, and open systems.

EIA


The Electronic Industries Association is a trade organization that has developed standards such as the RS-232 standard for terminals and computer connections.

IEEE


The Institute of Electrical and Electronic Engineers is a professional organization that develops standards and submits them for ANSI approval.
The IEEE 1003.1 standard, announced in 1988, is the official POSIX (Portable Operating System Interface for Computer Environments) standard for application portability in open systems. Along with many other POSIX standards efforts, it was developed in cooperation with the ISO (described below). Although the POSIX interface standard (also known as POSIX-1) is based on the UNIX system model, POSIX specifies how an interface must perform, not how it is implemented, so UNIX need not be the base operating system. POSIX.1 evolved in 1981 from /usr/group, the forerunner of UniForum, the Association of UNIX System Users. The /usr/group standard was an early attempt to specify a standard for a portable mechanism.
The IEEE 1003.1 standard has also been published by NIST (described below) as FIPS PUB 151 and by ISO (also described below) as ISO/IEC 9945-1.

IEEE has a number of committees, some of them security-related. The IEEE 1003.6 Security Extensions Committee grew out of UniForum's Technical Committee's Security Subcommittee. This committee is dedicated to developing standards for making a POSIX-compliant system a trusted system. Security subgroups are at work on security issues such as discretionary access control, mandatory access control, privileges, and audit trails, and standards are expected within the next few years.

IFIP The International Federation of Information Processing is a multinational federation of professional and technical organizations involved with computer and information processing. It was originally established under the auspices of UNESCO. IFIP has a number of committees. The Technical Committee 11 (TC-11) on Security and Protection in Information Systems does extensive work in proliferating security information internationally and in developing standards.

ISO The International Standards Organization (Organisation Internationale de Normalisation) founded in 1946, is an international organization composed of a number of national standards organizations. ISO's Open Systems Interconnection (OSI) basic reference model is a standard conceptual model for discussing data communications. ISO and other organizations are working on extending the OSI model to define security-related architectural elements.
Several groups within ISO are developing standards using cryptography as a mechanism for network security. Such standards will provide for data confidentiality, data integrity, peer entity authentication, access control, key distribution, and digital signatures.

MAP/TOP


The Manufacturing Automation Protocol/Technical Office Protocol is a consortium of factory automation users. Sponsored by General Motors (MAP) and Boeing (TOP), MAP/TOP has worked on pieces of ISO standards.

NCSC


The National Computer Security Center publishes the Rainbow Series of computer security standards for trusted systems, chief among them the Orange Book.
The NCSC sponsors the Trusted UNIX Organization, which consists of a group of vendors, including AT&T, involved in developing trusted UNIX systems. Security standards developed by TRUSIX will be POSIX-compliant.

NIST


The National Institute of Standards and Technology (formerly the National Bureau of Standards) specifies standards for many government-related products and procedures.
FIPS PUBs (Federation of Information Processing Standards publications) are written by NIST's National Computer Systems Laboratory (NCSL). FIPS PUBs are required standards for the acquisition of equipment and the processing of information by government agencies and contractors.

GOSIP (the Government Open Systems Interconnect Profile program) is sponsored by NIST with participation by a number of other government agencies. GOSIP specifies a set of data communications protocols based on the OSI model. All government agencies that buy networks must now comply with the GOSIP/OSI standard. In 1988, Version 1 of the GOSIP standard for networks and services was published as FIPS PUB 146. The standard is being revised to address security concerns and other issues.

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Computer Security

With computer systems increasingly under attack, it's no wonder that people are starting to take computer security more seriously. But despite this increased interest, many computer users still don't really understand what computer security is-and why it should be important to them. The headlines about the Internet worm, KGB agents, and million-dollar funds transfer frauds tell only part of the story, and it's a part most of us can't identify with as a day-to-day concern.

Computer security protects your computer and everything associated with it-your building, your terminals and printers, your cabling, and your disks and tapes. Most importantly, computer security protects the information you've stored in your system. That's why computer security is often called information security.

There's a longstanding view of computer security that its purpose is to protect against one particular danger-outside intruders who break into systems to steal money or secrets, or simply to prove they can do it. And although such intruders do exist, they aren't the only, or even the primary, danger to computer systems. There are many more immediate dangers, ranging from sharing your password with a friend, to failing to back up a disk, to spilling a soda on a terminal keyboard. These dangers aren't as newsworthy as flamboyantly named viruses, but
they're more likely to cause you problems on a daily basis. The following sections define computer security and outline the wide range of dangers to computer systems

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Microsoft Develops New Operating System From Scratch

Microsoft showed off a new operating system on Tuesday, but don't get too excited.

Think of Singularity as "a concept-car OS," said Rick Rashid, general director of Microsoft Research. Microsoft is making the prototype OS available free to the academic and research communities in the hope that they'll use it to develop new kinds of computer architectures.

It's difficult for the academic community to experiment with computer architectures, he said. Singularity is designed to make it easier for researchers to test how operating systems and applications interact with each other, he said.

"It's a new system built from the ground up, with the specific goal of being more reliable," Rashid said. Microsoft hopes that Singularity will help improve software reliability and boost research in programming languages and tools.Singularity is available on Microsoft's CodePlex Web site. It was unveiled on Tuesday at TechFest, Microsoft's annual showcase of projects from its research division.

Rashid also showed off BEE3, a hardware project that Microsoft designed with researchers at the University of California, Berkeley to let researchers experiment with computer architectures. "The idea behind it is to build a computer system that is configurable," Rashid said. "You can program this computer to be another computer or do another kind of architecture or experiment with new kinds of algorithms," he said.

Rashid and his colleagues are demonstrating technologies that Microsoft's research group is working on. Some of the projects ultimately contribute to Microsoft products but others, like vaccine design and quantum computing, often seem irrelevant to the software giant's core business.
irrelevant to the software giant's core business.

Still, Rashid said that the best return on any investment that Microsoft makes consistently comes from its investment in Microsoft Research. The group generates about a quarter of the company's patents, he said.

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