Glulx
Encyclopedia
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.
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.
Despite being a better-adapted virtual machine for modern computing hardware and being just as accessible to developers, Glulx continues to lag behind the Z-machine in popularity, largely due to the comparative rarity of interpreters. The most popular interpreter for Glulx is Andrew Plotkin's Glulxe. Glulxe uses the Glk API for input and output.
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.
32-bit
The range of integer values that can be stored in 32 bits is 0 through 4,294,967,295. Hence, a processor with 32-bit memory addresses can directly access 4 GB of byte-addressable memory....
portable
Porting
In computer science, porting is the process of adapting software so that an executable program can be created for a computing environment that is different from the one for which it was originally designed...
virtual machine
Virtual machine
A virtual machine is a "completely isolated guest operating system installation within a normal host operating system". Modern virtual machines are implemented with either software emulation or hardware virtualization or both together.-VM Definitions:A virtual machine is a software...
intended for writing and playing interactive fiction
Interactive fiction
Interactive fiction, often abbreviated IF, describes 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 and as video games. In common usage, the term refers to text...
. It was designed by Andrew Plotkin
Andrew Plotkin
Andrew Plotkin , also known as Zarf, is a central figure in the modern interactive fiction 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...
to relieve some of the restrictions in the venerable Z-machine
Z-machine
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 all its text adventures to a new platform simply by writing a...
format. For example, the Z-machine provides native support for 16-bit integers, while Glulx natively supports 32-bit integers.
The Inform
Inform
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.- Z-Machine and...
compiler
Compiler
A compiler is a computer program that transforms source code written in a programming language into another computer language...
, starting with version 6.30, can produce either Z-machine
Z-machine
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 all its text adventures to a new platform simply by writing a...
or Glulx story files. A Spanish interactive fiction development system called Superglús also uses Glulx.
Despite being a better-adapted virtual machine for modern computing hardware and being just as accessible to developers, Glulx continues to lag behind the Z-machine in popularity, largely due to the comparative rarity of interpreters. The most popular interpreter for Glulx is Andrew Plotkin's Glulxe. Glulxe uses the Glk API for input and output.
The MIME
MIME
Multipurpose Internet Mail Extensions is an Internet standard that extends the format of email to support:* Text in character sets other than ASCII* Non-text attachments* Message bodies with multiple parts...
type for Glulx is "application/x-glulx".
Glulx files have the file extension .ulx, but they are commonly archived in Blorb
Blorb
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...
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
Blorb
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...
file.