Glk is a portable

application programming interface An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how ...

(API) created by Andrew Plotkin for use by programs with a text

interface Interface or interfacing may refer to: Academic journals * ''Interface'' (journal), by the Electrochemical Society * '' Interface, Journal of Applied Linguistics'', now merged with ''ITL International Journal of Applied Linguistics'' * '' Int ...

; these programs mostly include

interactive fiction '' Interactive fiction, often abbreviated IF, is software simulating environments in which players use text commands to control characters and influence the environment. Works in this form can be understood as literary narratives, either in the ...

(IF)

interpreters Interpreting is a translational activity in which one produces a first and final target-language output on the basis of a one-time exposure to an expression in a source language. The most common two modes of interpreting are simultaneous interp ...

for Z-machine,

TADS Text Adventure Development System (TADS) is a prototype-based domain-specific programming language and set of standard libraries for creating interactive fiction (IF) games. History The original TADS 1 was released by High Energy Software a ...

Glulx Glulx is a 32-bit portable virtual machine intended for writing and playing interactive fiction. It was designed by Andrew Plotkin to relieve some of the restrictions in the venerable Z-machine format. For example, the Z-machine provides native ...

, and Hugo games, and IF games written in more obscure file formats such as those used by

Level 9 Computing Level 9 was a British developer of computer software, active between 1981 and 1991. Founded by Mike, Nicholas and Pete Austin, the company produced software for the BBC Micro, Nascom, ZX Spectrum, Commodore 64, Oric, Atari, Lynx 48k, RML 380Z ...

and

Magnetic Scrolls Magnetic Scrolls was a British video game developer active between 1984 and 1990. A pioneer of audiovisually elaborate text adventure games, it was one of the two largest and most acclaimed interactive fiction developers of the 1980s. ''Magneti ...

. The Glk API specification describes facilities for

input Input may refer to: Computing * Input (computer science), the act of entering data into a computer or data processing system * Information, any data entered into a computer or data processing system * Input device * Input method * Input port (disa ...

, output, text formatting,

graphics Graphics () are visual images or designs on some surface, such as a wall, canvas, screen, paper, or stone, to inform, illustrate, or entertain. In contemporary usage, it includes a pictorial representation of data, as in design and manufacture, ...

sound In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by ...

, and file I/O. Glk does not describe a

virtual machine In computing, a virtual machine (VM) is the virtualization/ emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer. Their implementations may involve specialized h ...

is a virtual machine designed to be implemented using the Glk functions, and Glulxe is an interpreter for Glulx. Interpreters for other virtual machines may use Glk while being unrelated to Glulx: for example,

Nitfol The Z-machine is a virtual machine that was developed by Joel Berez and Marc Blank in 1979 and used by Infocom for its text adventure games. Infocom compiled game code to files containing Z-machine instructions (called story files or Z-code f ...

is an interpreter for the Z-Machine that uses Glk. The Glk API has many

implementation Implementation is the realization of an application, or execution of a plan, idea, model, design, specification, standard, algorithm, or policy. Industry-specific definitions Computer science In computer science, an implementation is a real ...

s, including GlkTerm,

ScummVM Script Creation Utility for Maniac Mansion Virtual Machine (ScummVM) is a set of game engine recreations. Originally designed to play LucasArts adventure games that use the SCUMM system, it also supports a variety of non-SCUMM games by companies ...

's Glk, WindowsGlk, XGlk. Implementations are available on the following platforms: *

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

JavaScript JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of websites use JavaScript on the client side for webpage behavior, of ...

http://eblong.com/zarf/glk/glkote.html: GlkOte: a JavaScript library for IF interfaces (retrieved 2012-05-03) *

Macintosh The Mac (known as Macintosh until 1999) is a family of personal computers designed and marketed by Apple Inc., Apple Inc. Macs are known for their ease of use and minimalist designs, and are popular among students, creative professionals, and ...

DOS DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems. DOS may also refer to: Computing * Data over signalling (DoS), multiplexing data onto a signalling channel * Denial-of-service attack (DoS), an attack on a communicat ...

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, ...

X Window System The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting wi ...

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ...

Pocket PC A Pocket PC (P/PC, PPC) is a class of personal digital assistant (PDA) that runs the Windows Mobile or Windows Embedded Compact operating system that has some of the abilities of modern desktop PCs. The name was introduced by Microsoft in 200 ...

The existence of the Glk API has made possible the creation of "universal translator" IF interpreters, programs such as ''Gargoyle'' and ''Spatterlight'' which can run all popular IF formats and almost all of the more obscure ones. Such programs are very useful for newcomers to the medium who are unsure of which interpreter to choose, and to experienced players who may possess games in a variety of formats.

References

External links

GLK API specification
Programming tools for Windows Unix software {{Unix-stub