SPARC is a reduced instruction set computing instruction set architecture developed by Sun Microsystems. Its design was influenced by the experimental Berkeley RISC system developed in the early 1980s. First released in 1987, SPARC was one of the most successful early commercial RISC systems, its success led to the introduction of similar RISC designs from a number of vendors through the 1980s and 90s; the first implementation of the original 32-bit architecture was used in Sun's Sun-4 workstation and server systems, replacing their earlier Sun-3 systems based on the Motorola 68000 series of processors. SPARC V8 added a number of improvements that were part of the SuperSPARC series of processors released in 1992. SPARC V9, released in 1993, introduced a 64-bit architecture and was first released in Sun's UltraSPARC processors in 1995. SPARC processors were used in symmetric multiprocessing and non-uniform memory access servers produced by Sun and Fujitsu, among others; the design was turned over to the SPARC International trade group in 1989, since its architecture has been developed by its members.
SPARC International is responsible for licensing and promoting the SPARC architecture, managing SPARC trademarks, providing conformance testing. SPARC International was intended to grow the SPARC architecture to create a larger ecosystem. Due to SPARC International, SPARC is open, non-proprietary and royalty-free; as of September 2017, the latest commercial high-end SPARC processors are Fujitsu's SPARC64 XII and SPARC64 XIfx. On Friday, September 1, 2017, after a round of layoffs that started in Oracle Labs in November 2016, Oracle terminated SPARC design after the completion of the M8. Much of the processor core development group in Austin, was dismissed, as were the teams in Santa Clara and Burlington, Massachusetts. SPARC development continues with Fujitsu returning to the role of leading provider of SPARC servers, with a new CPU due in the 2020 time frame; the SPARC architecture was influenced by the earlier RISC designs, including the RISC I and II from the University of California and the IBM 801.
These original RISC designs were minimalist, including as few features or op-codes as possible and aiming to execute instructions at a rate of one instruction per clock cycle. This made them similar to the MIPS architecture in many ways, including the lack of instructions such as multiply or divide. Another feature of SPARC influenced by this early RISC movement is the branch delay slot; the SPARC processor contains as many as 160 general purpose registers. According to the "Oracle SPARC Architecture 2015" specification an "implementation may contain from 72 to 640 general-purpose 64-bit" registers. At any point, only 32 of them are visible to software — 8 are a set of global registers and the other 24 are from the stack of registers; these 24 registers form what is called a register window, at function call/return, this window is moved up and down the register stack. Each window has 8 local shares 8 registers with each of the adjacent windows; the shared registers are used for passing function parameters and returning values, the local registers are used for retaining local values across function calls.
The "Scalable" in SPARC comes from the fact that the SPARC specification allows implementations to scale from embedded processors up through large server processors, all sharing the same core instruction set. One of the architectural parameters that can scale is the number of implemented register windows. Other architectures that include similar register file features include Intel i960, IA-64, AMD 29000; the architecture has gone through several revisions. It gained hardware multiply and divide functionality in Version 8. 64-bit were added to the version 9 SPARC specification published in 1994. In SPARC Version 8, the floating point register file has 16 double-precision registers; each of them can be used as two single-precision registers, providing a total of 32 single precision registers. An odd-even number pair of double precision registers can be used as a quad-precision register, thus allowing 8 quad precision registers. SPARC Version 9 added 16 more double precision registers, but these additional registers can not be accessed as single precision registers.
No SPARC CPU implements quad-precision operations in hardware as of 2004. Tagged add and subtract instructions perform adds and subtracts on values checking that the bottom two bits of both operands are 0 and reporting overflow if they are not; this can be useful in the implementation of the run time for ML, similar languages that might use a tagged integer format. The endianness of the 32-bit SPARC V8 architecture is purely big-endian; the 64-bit SPARC V9 architecture uses big-endian instructions, but can access data in either big-endian or little-endian byte order, cho
Linux is a family of free and open-source software operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is packaged in a Linux distribution. Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian and Ubuntu. Commercial distributions include SUSE Linux Enterprise Server. Desktop Linux distributions include a windowing system such as X11 or Wayland, a desktop environment such as GNOME or KDE Plasma. Distributions intended for servers may omit graphics altogether, include a solution stack such as LAMP; because Linux is redistributable, anyone may create a distribution for any purpose. Linux was developed for personal computers based on the Intel x86 architecture, but has since been ported to more platforms than any other operating system.
Linux is the leading operating system on servers and other big iron systems such as mainframe computers, the only OS used on TOP500 supercomputers. It is used by around 2.3 percent of desktop computers. The Chromebook, which runs the Linux kernel-based Chrome OS, dominates the US K–12 education market and represents nearly 20 percent of sub-$300 notebook sales in the US. Linux runs on embedded systems, i.e. devices whose operating system is built into the firmware and is tailored to the system. This includes routers, automation controls, digital video recorders, video game consoles, smartwatches. Many smartphones and tablet computers run other Linux derivatives; because of the dominance of Android on smartphones, Linux has the largest installed base of all general-purpose operating systems. Linux is one of the most prominent examples of open-source software collaboration; the source code may be used and distributed—commercially or non-commercially—by anyone under the terms of its respective licenses, such as the GNU General Public License.
The Unix operating system was conceived and implemented in 1969, at AT&T's Bell Laboratories in the United States by Ken Thompson, Dennis Ritchie, Douglas McIlroy, Joe Ossanna. First released in 1971, Unix was written in assembly language, as was common practice at the time. In a key pioneering approach in 1973, it was rewritten in the C programming language by Dennis Ritchie; the availability of a high-level language implementation of Unix made its porting to different computer platforms easier. Due to an earlier antitrust case forbidding it from entering the computer business, AT&T was required to license the operating system's source code to anyone who asked; as a result, Unix grew and became adopted by academic institutions and businesses. In 1984, AT&T divested itself of Bell Labs; the GNU Project, started in 1983 by Richard Stallman, had the goal of creating a "complete Unix-compatible software system" composed of free software. Work began in 1984. In 1985, Stallman started the Free Software Foundation and wrote the GNU General Public License in 1989.
By the early 1990s, many of the programs required in an operating system were completed, although low-level elements such as device drivers and the kernel, called GNU/Hurd, were stalled and incomplete. Linus Torvalds has stated that if the GNU kernel had been available at the time, he would not have decided to write his own. Although not released until 1992, due to legal complications, development of 386BSD, from which NetBSD, OpenBSD and FreeBSD descended, predated that of Linux. Torvalds has stated that if 386BSD had been available at the time, he would not have created Linux. MINIX was created by Andrew S. Tanenbaum, a computer science professor, released in 1987 as a minimal Unix-like operating system targeted at students and others who wanted to learn the operating system principles. Although the complete source code of MINIX was available, the licensing terms prevented it from being free software until the licensing changed in April 2000. In 1991, while attending the University of Helsinki, Torvalds became curious about operating systems.
Frustrated by the licensing of MINIX, which at the time limited it to educational use only, he began to work on his own operating system kernel, which became the Linux kernel. Torvalds began the development of the Linux kernel on MINIX and applications written for MINIX were used on Linux. Linux matured and further Linux kernel development took place on Linux systems. GNU applications replaced all MINIX components, because it was advantageous to use the available code from the GNU Project with the fledgling operating system. Torvalds initiated a switch from his original license, which prohibited commercial redistribution, to the GNU GPL. Developers worked to integrate GNU components with the Linux kernel, making a functional and free operating system. Linus Torvalds had wanted to call his invention "Freax", a portmant
X86 is a family of instruction set architectures based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was introduced in 1978 as a 16-bit extension of Intel's 8-bit 8080 microprocessor, with memory segmentation as a solution for addressing more memory than can be covered by a plain 16-bit address; the term "x86" came into being because the names of several successors to Intel's 8086 processor end in "86", including the 80186, 80286, 80386 and 80486 processors. Many additions and extensions have been added to the x86 instruction set over the years consistently with full backward compatibility; the architecture has been implemented in processors from Intel, Cyrix, AMD, VIA and many other companies. Of those, only Intel, AMD, VIA hold x86 architectural licenses, are producing modern 64-bit designs; the term is not synonymous with IBM PC compatibility, as this implies a multitude of other computer hardware. As of 2018, the majority of personal computers and laptops sold are based on the x86 architecture, while other categories—especially high-volume mobile categories such as smartphones or tablets—are dominated by ARM.
In the 1980s and early 1990s, when the 8088 and 80286 were still in common use, the term x86 represented any 8086 compatible CPU. Today, however, x86 implies a binary compatibility with the 32-bit instruction set of the 80386; this is due to the fact that this instruction set has become something of a lowest common denominator for many modern operating systems and also because the term became common after the introduction of the 80386 in 1985. A few years after the introduction of the 8086 and 8088, Intel added some complexity to its naming scheme and terminology as the "iAPX" of the ambitious but ill-fated Intel iAPX 432 processor was tried on the more successful 8086 family of chips, applied as a kind of system-level prefix. An 8086 system, including coprocessors such as 8087 and 8089, as well as simpler Intel-specific system chips, was thereby described as an iAPX 86 system. There were terms iRMX, iSBC, iSBX – all together under the heading Microsystem 80. However, this naming scheme was quite temporary.
Although the 8086 was developed for embedded systems and small multi-user or single-user computers as a response to the successful 8080-compatible Zilog Z80, the x86 line soon grew in features and processing power. Today, x86 is ubiquitous in both stationary and portable personal computers, is used in midrange computers, workstations and most new supercomputer clusters of the TOP500 list. A large amount of software, including a large list of x86 operating systems are using x86-based hardware. Modern x86 is uncommon in embedded systems and small low power applications as well as low-cost microprocessor markets, such as home appliances and toys, lack any significant x86 presence. Simple 8-bit and 16-bit based architectures are common here, although the x86-compatible VIA C7, VIA Nano, AMD's Geode, Athlon Neo and Intel Atom are examples of 32- and 64-bit designs used in some low power and low cost segments. There have been several attempts, including by Intel itself, to end the market dominance of the "inelegant" x86 architecture designed directly from the first simple 8-bit microprocessors.
Examples of this are the iAPX 432, the Intel 960, Intel 860 and the Intel/Hewlett-Packard Itanium architecture. However, the continuous refinement of x86 microarchitectures and semiconductor manufacturing would make it hard to replace x86 in many segments. AMD's 64-bit extension of x86 and the scalability of x86 chips such as the eight-core Intel Xeon and 12-core AMD Opteron is underlining x86 as an example of how continuous refinement of established industry standards can resist the competition from new architectures; the table below lists processor models and model series implementing variations of the x86 instruction set, in chronological order. Each line item is characterized by improved or commercially successful processor microarchitecture designs. At various times, companies such as IBM, NEC, AMD, TI, STM, Fujitsu, OKI, Cyrix, Intersil, C&T, NexGen, UMC, DM&P started to design or manufacture x86 processors intended for personal computers as well as embedded systems; such x86 implementations are simple copies but employ different internal microarchitectures as well as different solutions at the electronic and physical levels.
Quite early compatible microprocessors were 16-bit, while 32-bit designs were developed much later. For the personal computer market, real quantities started to appear around 1990 with i386 and i486 compatible processors named to Intel's original chips. Other companies, which designed or manufactured x86 or x87 processors, include ITT Corporation, National Semiconductor, ULSI System Technology, Weitek. Following the pipelined i486, Intel introduced the Pentium brand name for their new set of superscalar x86 designs.
PowerPC is a reduced instruction set computing instruction set architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM. PowerPC, as an evolving instruction set, has since 2006 been named Power ISA, while the old name lives on as a trademark for some implementations of Power Architecture-based processors. PowerPC was the cornerstone of AIM's PReP and Common Hardware Reference Platform initiatives in the 1990s. Intended for personal computers, the architecture is well known for being used by Apple's Power Macintosh, PowerBook, iMac, iBook, Xserve lines from 1994 until 2006, when Apple migrated to Intel's x86, it has since become a niche in personal computers, but remains popular for embedded and high-performance processors. Its use in 7th generation of video game consoles and embedded applications provided an array of uses. In addition, PowerPC CPUs are still used in third party AmigaOS 4 personal computers. PowerPC is based on IBM's earlier POWER instruction set architecture, retains a high level of compatibility with it.
The history of RISC began with IBM's 801 research project, on which John Cocke was the lead developer, where he developed the concepts of RISC in 1975–78. 801-based microprocessors were used in a number of IBM embedded products becoming the 16-register IBM ROMP processor used in the IBM RT PC. The RT PC was a rapid design implementing the RISC architecture. Between the years of 1982–1984, IBM started a project to build the fastest microprocessor on the market; the result is the POWER instruction set architecture, introduced with the RISC System/6000 in early 1990. The original POWER microprocessor, one of the first superscalar RISC implementations, is a high performance, multi-chip design. IBM soon realized that a single-chip microprocessor was needed in order to scale its RS/6000 line from lower-end to high-end machines. Work began on a one-chip POWER microprocessor, designated the RSC. In early 1991, IBM realized its design could become a high-volume microprocessor used across the industry. Apple had realized the limitations and risks of its dependency upon a single CPU vendor at a time when Motorola was falling behind on delivering the 68040 CPU.
Furthermore, Apple had conducted its own research and made an experimental quad-core CPU design called Aquarius, which convinced the company's technology leadership that the future of computing was in the RISC methodology. IBM approached Apple with the goal of collaborating on the development of a family of single-chip microprocessors based on the POWER architecture. Soon after, being one of Motorola's largest customers of desktop-class microprocessors, asked Motorola to join the discussions due to their long relationship, Motorola having had more extensive experience with manufacturing high-volume microprocessors than IBM, to form a second source for the microprocessors; this three-way collaboration between Apple, IBM, Motorola became known as the AIM alliance. In 1991, the PowerPC was just one facet of a larger alliance among these three companies. At the time, most of the personal computer industry was shipping systems based on the Intel 80386 and 80486 chips, which have a complex instruction set computer architecture, development of the Pentium processor was well underway.
The PowerPC chip was one of several joint ventures involving the three alliance members, in their efforts to counter the growing Microsoft-Intel dominance of personal computing. For Motorola, POWER looked like an unbelievable deal, it allowed the company to sell a tested and powerful RISC CPU for little design cash on its own part. It maintained ties with an important customer and seemed to offer the possibility of adding IBM too, which might buy smaller versions from Motorola instead of making its own. At this point Motorola had its own RISC design in the form of the 88000, doing poorly in the market. Motorola was doing well with its 68000 family and the majority of the funding was focused on this; the 88000 effort was somewhat starved for resources. The 88000 was in production, however; the 88000 had achieved a number of embedded design wins in telecom applications. If the new POWER one-chip version could be made bus-compatible at a hardware level with the 88000, that would allow both Apple and Motorola to bring machines to market far faster since they would not have to redesign their board architecture.
The result of these various requirements is the PowerPC specification. The differences between the earlier POWER instruction set and that of PowerPC is outlined in Appendix E of the manual for PowerPC ISA v.2.02. Since 1991, IBM had a long-standing desire for a unifying operating system that would host all existing operating systems as personalities upon one microkernel. From 1991 to 1995, the company designed and aggressively evangelized what would become Workplace OS targeting PowerPC; when the first PowerPC products reached the market, they were met with enthusiasm. In addition to Apple, both IBM and the Motorola Computer Group offered systems built around the processors. Microsoft released Windows NT 3.51 for the architecture, used in Motorola's
X86-64 is the 64-bit version of the x86 instruction set. It introduces two new modes of operation, 64-bit mode and compatibility mode, along with a new 4-level paging mode. With 64-bit mode and the new paging mode, it supports vastly larger amounts of virtual memory and physical memory than is possible on its 32-bit predecessors, allowing programs to store larger amounts of data in memory. X86-64 expands general-purpose registers to 64-bit, as well extends the number of them from 8 to 16, provides numerous other enhancements. Floating point operations are supported via mandatory SSE2-like instructions, x87/MMX style registers are not used. In 64-bit mode, instructions are modified to support 64-bit addressing mode; the compatibility mode allows 16- and 32-bit user applications to run unmodified coexisting with 64-bit applications if the 64-bit operating system supports them. As the full x86 16-bit and 32-bit instruction sets remain implemented in hardware without any intervening emulation, these older executables can run with little or no performance penalty, while newer or modified applications can take advantage of new features of the processor design to achieve performance improvements.
A processor supporting x86-64 still powers on in real mode for full backward compatibility. The original specification, created by AMD and released in 2000, has been implemented by AMD, Intel and VIA; the AMD K8 processor was the first to implement it. This was the first significant addition to the x86 architecture designed by a company other than Intel. Intel was forced to follow suit and introduced a modified NetBurst family, software-compatible with AMD's specification. VIA Technologies introduced x86-64 with the VIA Nano; the x86-64 architecture is distinct from the Intel Itanium architecture, not compatible on the native instruction set level with the x86 architecture. Operating systems and applications written for one cannot be run on the other. AMD64 was created as an alternative to the radically different IA-64 architecture, designed by Intel and Hewlett Packard. Announced in 1999 while a full specification became available in August 2000, the AMD64 architecture was positioned by AMD from the beginning as an evolutionary way to add 64-bit computing capabilities to the existing x86 architecture, as opposed to Intel's approach of creating an new 64-bit architecture with IA-64.
The first AMD64-based processor, the Opteron, was released in April 2003. AMD's processors implementing the AMD64 architecture include Opteron, Athlon 64, Athlon 64 X2, Athlon 64 FX, Athlon II, Turion 64, Turion 64 X2, Phenom, Phenom II, FX, Fusion/APU and Ryzen/Epyc; the primary defining characteristic of AMD64 is the availability of 64-bit general-purpose processor registers, 64-bit integer arithmetic and logical operations, 64-bit virtual addresses. The designers took the opportunity to make other improvements as well; some of the most significant changes are described below. 64-bit integer capability All general-purpose registers are expanded from 32 bits to 64 bits, all arithmetic and logical operations, memory-to-register and register-to-memory operations, etc. can now operate directly on 64-bit integers. Pushes and pops on the stack default to 8-byte strides, pointers are 8 bytes wide. Additional registers In addition to increasing the size of the general-purpose registers, the number of named general-purpose registers is increased from eight in x86 to 16.
It is therefore possible to keep more local variables in registers rather than on the stack, to let registers hold accessed constants. AMD64 still has fewer registers than many RISC instruction sets or VLIW-like machines such as the IA-64. However, an AMD64 implementation may have far more internal registers than the number of architectural registers exposed by the instruction set. Additional XMM registers Similarly, the number of 128-bit XMM registers is increased from 8 to 16; the traditional x87 FPU register stack is not included in the register file size extension in 64-bit mode, compared with the XMM registers used by SSE2, which did get extended. The x87 register stack is not a simple register file although it does allow direct access to individual registers by low cost exchange operations. Larger virtual address space The AMD64 architecture defines a 64-bit virtual address format, of which the low-order 48 bits are used in current implementations; this allows up to 256 TB of virtual address space.
The architecture definition allows this limit to be raised in future implementations to the full 64 bits, exten
OS/2 is a series of computer operating systems created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 relative to Microsoft's new Windows 3.1 operating environment, the two companies severed the relationship in 1992 and OS/2 development fell to IBM exclusively. The name stands for "Operating System/2", because it was introduced as part of the same generation change release as IBM's "Personal System/2" line of second-generation personal computers; the first version of OS/2 was released in December 1987 and newer versions were released until December 2001. OS/2 was intended as a protected-mode successor of PC DOS. Notably, basic system calls were modeled after MS-DOS calls; because of this heritage, OS/2 shares similarities with Unix and Windows NT. IBM discontinued its support for OS/2 on 31 December 2006. Since it has been updated and marketed under the name eComStation. In 2015 it was announced that a new OEM distribution of OS/2 would be released, to be called ArcaOS.
ArcaOS is available for purchase. The development of OS/2 began when IBM and Microsoft signed the "Joint Development Agreement" in August 1985, it was code-named "CP/DOS" and it took two years for the first product to be delivered. OS/2 1.0 was released in December. The original release is textmode-only, a GUI was introduced with OS/2 1.1 about a year later. OS/2 features an API for controlling the video display and handling keyboard and mouse events so that programmers writing for protected-mode need not call the BIOS or access hardware directly. Other development tools included a subset of the video and keyboard APIs as linkable libraries so that family mode programs are able to run under MS-DOS, and, in the OS/2 Extended Edition v1.0, a database engine called Database Manager or DBM. A task-switcher named Program Selector was available through the Ctrl-Esc hotkey combination, allowing the user to select among multitasked text-mode sessions. Communications and database-oriented extensions were delivered in 1988, as part of OS/2 1.0 Extended Edition: SNA, X.25/APPC/LU 6.2, LAN Manager, Query Manager, SQL.
The promised user interface, Presentation Manager, was introduced with OS/2 1.1 in October 1988. It had a similar user interface to Windows 2.1, released in May of that year.. The Extended Edition of 1.1, sold only through IBM sales channels, introduced distributed database support to IBM database systems and SNA communications support to IBM mainframe networks. In 1989, Version 1.2 introduced Installable Filesystems and, the HPFS filesystem. HPFS provided a number of improvements over the older FAT file system, including long filenames and a form of alternate data streams called Extended Attributes. In addition, extended attributes were added to the FAT file system; the Extended Edition of 1.2 introduced Ethernet support. OS/2- and Windows-related books of the late 1980s acknowledged the existence of both systems and promoted OS/2 as the system of the future; the collaboration between IBM and Microsoft unravelled in 1990, between the releases of Windows 3.0 and OS/2 1.3. During this time, Windows 3.0 became a tremendous success, selling millions of copies in its first year.
Much of its success was. OS/2, on the other hand, was available only as an additional stand-alone software package. In addition, OS/2 lacked device drivers for many common devices such as printers non-IBM hardware. Windows, on the other hand, supported a much larger variety of hardware; the increasing popularity of Windows prompted Microsoft to shift its development focus from cooperating on OS/2 with IBM to building its own business based on Windows. Several technical and practical reasons contributed to this breakup; the two companies had significant differences in vision. Microsoft favored the open hardware system approach that contributed to its success on the PC. Microsoft programmers became frustrated with IBM's bureaucracy and its use of lines of code to measure programmer productivity. IBM developers complained about the terseness and lack of comments in Microsoft's code, while Microsoft developers complained that IBM's code was bloated; the two products have significant differences in API.
OS/2 was announced when Windows 2.0 was near completion, the Windows API defined. However, IBM requested that this API be changed for OS/2. Therefore, issues surrounding application compatibility appeared immediately. OS/2 designers hoped for source code conversion tools, allowing complete migration of Windows application source code to OS/2 at some point. However, OS/2 1.x did not gain enough momentum to allow vendors to avoid developing for both OS/2 and Windows in parallel. OS/2 1.x targets DOS fundamentally doesn't. IBM insisted on supporting the 80286 processor, with its 16-bit segmented memory mode, because of commitments made to customers who had purchased many 80286-based PS/2s as a result of IBM's promises surrounding OS/2; until release 2.0 in April 1992, OS/2 ran in 16-bit protected mode and therefor
"Hello, World!" program
A "Hello, World!" program is a computer program that outputs or displays the message "Hello, World!". Because it is simple in most programming languages, it is used to illustrate the basic syntax of a programming language and is the first program that those learning to code write. A "Hello, World!" program is traditionally used to introduce novice programmers to a programming language. "Hello, world!" is traditionally used in a sanity test to make sure that a computer language is installed, that the operator understands how to use it. While small test programs have existed since the development of programmable computers, the tradition of using the phrase "Hello, world!" as a test message was influenced by an example program in the seminal book The C Programming Language. The example program from that book prints "hello, world", was inherited from a 1974 Bell Laboratories internal memorandum by Brian Kernighan, Programming in C: A Tutorial: The C version was preceded by Kernighan's own 1972 A Tutorial Introduction to the Language B, where the first known version of the program is found in an example used to illustrate external variables: main a'hell'.
The phrase is divided into multiple variables because in B, a character constant is limited to four ASCII characters. The previous example in the tutorial printed hi! on the terminal, the phrase hello, world! was introduced as a longer greeting that required several character constants for its expression. The Jargon File claims that hello, world originated instead with BCPL; this claim is supported by the archived notes of the inventors of BCPL, Prof. Brian Kernighan at Princeton and Martin Richards at Cambridge. For modern languages, world programs vary in sophistication. For example, the Go programming language introduced a multilingual program, Sun demonstrated a Java hello, world based on scalable vector graphics, the XL programming language features a spinning Earth hello, world using 3D graphics. While some languages such as Perl, Python or Ruby may need only a single statement to print "hello, world", a low-level assembly language may require dozens of commands. Mark Guzdial and Elliot Soloway have suggested that the "hello, world" test message may be outdated now that graphics and sound can be manipulated as as text.
There are many variations on the punctuation and casing of the phrase. Variations include the presence or absence of the comma and exclamation mark, the capitalization of the'H', both the'H' and the'W', or neither; some languages are forced to implement different forms, such as "HELLO WORLD", on systems that support only capital letters, while many "hello, world" programs in esoteric languages print out a modified string. For example, the first non-trivial Malbolge program printed "HEllO WORld", this having been determined to be good enough. There are variations in spirit, as well. Functional programming languages, like Lisp, ML and Haskell, tend to substitute a factorial program for Hello, World, as functional programming emphasizes recursive techniques, whereas the original examples emphasize I/O, which violates the spirit of pure functional programming by producing side effects. Languages otherwise capable of Hello, World may be used in embedded systems, where text output is either difficult or nonexistent.
For devices such as microcontrollers, field-programmable gate arrays, CPLD's, "Hello, World" may thus be substituted with a blinking LED, which demonstrates timing and interaction between components. The Debian and Ubuntu Linux distributions provide the "hello, world" program through the apt packaging system. While of itself useless, it serves as a sanity check and a simple example to newcomers of how to install a package, it is more useful for developers, however, as it provides an example of how to create a.deb package, either traditionally or using debhelper, the version of hello used, GNU Hello, serves as an example of how to write a GNU program. Time to "Hello World" is a metric for how long it takes to get a "Hello World" program running from scratch in a given programming language. "99 Bottles of Beer" as used in computer science Foobar Java Pet Store Just another Perl hacker List of basic computer science topics Trabb Pardo-Knuth algorithm List of hello world programs at Wikibooks Rösler, Wolfram.
"Hello World Collection". Helloworldcollection.de. "Hello world/Text". Rosetta Code. "Unsung Heroes of IT / Part One: Brian Kernighan". TheUnsungHeroesOfIT.com. Archived from the original on 2016-03-26. Retrieved 2014-08-23