Glulx

Last updated
Glulx
Designer Andrew Plotkin
Bits32
Introduced1999
Version3.1.2 (2010)
Design CISC
Endianness Big
OpenYes

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 support for 16-bit integers, while Glulx natively supports 32-bit integers.

Contents

Versions and popularity

The Inform compiler, starting with version 6.30, can produce either Z-machine or Glulx story files. A Spanish interactive fiction development system called Superglús also uses Glulx.

Glulx continues to trail the Z-machine in popularity despite being a virtual machine more suited for contemporary computing hardware and as accessible to developers. This is partly because interpreters are more scarce than on the Z-machine. The most popular interpreter for Glulx is Andrew Plotkin's Glulxe. [1] Glulxe uses the Glk API for input and output.

File and email extensions

The MIME type for Glulx is "application/x-glulx". Glulx files have the file extension .ulx, but they are commonly archived in Blorb packages. For Blorb packages containing a Glulx work, accepted file extensions are .gblorb, .glb, .blorb and .blb. The former two extensions are intended to make it easy for interpreters to figure out which type of game is inside the Blorb file.

Related Research Articles

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 form of Interactive narratives or Interactive narrations. These works can also be understood as a form of video game, either in the form of an adventure game or role-playing game. In common usage, the term refers to text adventures, a type of adventure game where the entire interface can be "text-only", however, graphical text adventure games, where the text is accompanied by graphics still fall under the text adventure category if the main way to interact with the game is by typing text. Some users of the term distinguish between interactive fiction, known as "Puzzle-free", that focuses on narrative, and "text adventures" that focus on puzzles.

<span class="mw-page-title-main">Java virtual machine</span> Virtual machine that runs Java programs

A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally describes what is required in a JVM implementation. Having a specification ensures interoperability of Java programs across different implementations so that program authors using the Java Development Kit (JDK) need not worry about idiosyncrasies of the underlying hardware platform.

Pascal is an imperative and procedural programming language, designed by Niklaus Wirth as a small, efficient language intended to encourage good programming practices using structured programming and data structuring. It is named after French mathematician, philosopher and physicist Blaise Pascal.

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 and could therefore port its text adventures to a new platform simply by writing a Z-machine implementation for that platform. With the large number of incompatible home computer systems in use at the time, this was an important advantage over using native code or developing a compiler for each system.

OCaml is a general-purpose, high-level, multi-paradigm programming language which extends the Caml dialect of ML with object-oriented features. OCaml was created in 1996 by Xavier Leroy, Jérôme Vouillon, Damien Doligez, Didier Rémy, Ascánder Suárez, and others.

<span class="mw-page-title-main">Endianness</span> Order of bytes in a computer word

In computing, endianness is the order in which bytes within a word of digital data are transmitted over a data communication medium or addressed in computer memory, counting only byte significance compared to earliness. Endianness is primarily expressed as big-endian (BE) or little-endian (LE), terms introduced by Danny Cohen into computer science for data ordering in an Internet Experiment Note published in 1980. The adjective endian has its origin in the writings of 18th century Anglo-Irish writer Jonathan Swift. In the 1726 novel Gulliver's Travels, he portrays the conflict between sects of Lilliputians divided into those breaking the shell of a boiled egg from the big end or from the little end. By analogy, a CPU may read a digital word big end first, or little end first.

AltiVec is a single-precision floating point and integer SIMD instruction set designed and owned by Apple, IBM, and Freescale Semiconductor — the AIM alliance. It is implemented on versions of the PowerPC processor architecture, including Motorola's G4, IBM's G5 and POWER6 processors, and P.A. Semi's PWRficient PA6T. AltiVec is a trademark owned solely by Freescale, so the system is also referred to as Velocity Engine by Apple and VMX by IBM and P.A. Semi.

In computing, Streaming SIMD Extensions (SSE) is a single instruction, multiple data (SIMD) instruction set extension to the x86 architecture, designed by Intel and introduced in 1999 in their Pentium III series of central processing units (CPUs) shortly after the appearance of Advanced Micro Devices (AMD's) 3DNow!. SSE contains 70 new instructions, most of which work on single precision floating-point data. SIMD instructions can greatly increase performance when exactly the same operations are to be performed on multiple data objects. Typical applications are digital signal processing and graphics processing.

In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit central processing units (CPU) and arithmetic logic units (ALU) are those that are based on processor registers, address buses, or data buses of that size. A computer that uses such a processor is a 64-bit computer.

Inform is a programming language and design system for interactive fiction originally created in 1993 by Graham Nelson. Inform can generate programs designed for the Z-code or Glulx virtual machines. Versions 1 through 5 were released between 1993 and 1996. Around 1996, Nelson rewrote Inform from first principles to create version 6. Over the following decade, version 6 became reasonably stable and a popular language for writing interactive fiction. In 2006, Nelson released Inform 7, a completely new language based on principles of natural language and a new set of tools based around a book-publishing metaphor.

x86-64 64-bit version of x86 architecture

x86-64 is a 64-bit version of the x86 instruction set, first announced in 1999. It introduced two new modes of operation, 64-bit mode and compatibility mode, along with a new 4-level paging mode.

Quetzal is a standardised file format for the saved state of Z-machine games, invented by Martin Frost. Prior to the introduction of Quetzal, each Z-machine interpreter saved games in its own format; Quetzal enabled players to save a game using one interpreter and restore it with another. Use of the format is strongly recommended in Graham Nelson's Z-machine standards document, but not obligatory. Most modern Z-machine interpreters have the ability to save Quetzal files.

<span class="mw-page-title-main">Andrew Plotkin</span> Interactive fiction programmer and writer

Andrew Plotkin, also known as Zarf, is a central figure in the modern interactive fiction (IF) community. Having both written a number of award-winning games and developed a range of new file formats, interpreters, and other utilities for the design, production, and running of IF games, Plotkin is widely recognised for both his creative and his technical contributions to the homebrew IF scene.

Glk is a portable application programming interface (API) created by Andrew Plotkin for use by programs with a text interface; these programs mostly include interactive fiction (IF) interpreters for Z-machine, TADS, Glulx, and Hugo games, and IF games written in more obscure file formats such as those used by Level 9 Computing and Magnetic Scrolls.

Blorb is a package format for interactive fiction games. Many such games incorporate resources such as sound effects, music, or pictures. Blorb's purpose is to bind these together into one file. The format was devised by Andrew Plotkin and is used in both the Z-machine and Glulx virtual machines, as well as by the Glk library.

In computer architecture, 31-bit integers, memory addresses, or other data units are those that are 31 bits wide.

Earth and Sky is an interactive fiction trilogy written and produced by American author Paul O'Brian about the adventures of a brother and sister who gain superpowers while searching for their lost parents. Games in the series have won awards in the annual Interactive Fiction Competition and received an XYZZY Award.

<span class="mw-page-title-main">OpenLisp</span>

OpenLisp is a programming language in the Lisp family developed by Christian Jullien from Eligis. It conforms to the international standard for ISLISP published jointly by the International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC), ISO/IEC 13816:1997(E), revised to ISO/IEC 13816:2007(E).

Java bytecode is the instruction set of the Java virtual machine (JVM), crucial for executing programs written in the Java language and other JVM-compatible languages. Each bytecode operation in the JVM is represented by a single byte, hence the name "bytecode", making it a compact form of instruction. This intermediate form enables Java programs to be platform-independent, as they are compiled not to native machine code but to a universally executable format across different JVM implementations.

References

  1. "Glulxe: The Glulx VM interpreter". GitHub . 25 October 2021.