Blorb is a package format for

interactive fiction Interactive fiction (IF) is software simulating environments in which players use text Command (computing), commands to control Player character, characters and influence the environment. Works in this form can be understood as literary narrati ...

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

s, as well as by the Glk library.

Concept

In the days when games were distributed only on disk, there was no problem in associating a game with its resources: the resources were simply shipped on the same disk. Since all Z-machine games were produced by

Infocom Infocom, Inc., was an American software company based in Cambridge, Massachusetts, that produced numerous works of interactive fiction. They also produced a business application, a relational database called ''Cornerstone (software), Cornerston ...

, there was also no chance that resources would be shipped in a format which a user's interpreter program could not handle. Blorb is needed because neither of these assumptions hold true in modern times: games are typically downloaded as single files, and a user may be using any of a large number of interpreters. A Blorb file may optionally include the

executable In computer science, executable code, an executable file, or an executable program, sometimes simply referred to as an executable or binary, causes a computer "to perform indicated tasks according to encoded instruction (computer science), in ...

code of the game itself. This allows authors of modern games to ship one file containing everything needed to play the game, while also allowing the creation of resource files for classic Infocom games without running the risk of

copyright infringement Copyright infringement (at times referred to as piracy) is the use of Copyright#Scope, works protected by copyright without permission for a usage where such permission is required, thereby infringing certain exclusive rights granted to the c ...

by distributing Infocom's Z-machine executable code. Glulx games are almost always shipped in the Blorb format. A rather smaller proportion of Z-machine games make use of it, since Z-machine games often rely only on text, and so have no need for the extra resources. As of 2004 Blorb files are supported by all Glk

interpreters, including Nitfol and Glulxe. The Blorb format continues the tradition of naming interactive fiction tools after spells in

's '' Enchanter'' trilogy. ''Blorb'' was a spell to bind objects into boxes. Blorb is an

IFF In logic and related fields such as mathematics and philosophy, "if and only if" (often shortened as "iff") is paraphrased by the biconditional, a logical connective between statements. The biconditional is true in two cases, where either both ...

format, with FORM IFRS. The

MIME A mime artist, or simply mime (from Greek language, Greek , , "imitator, actor"), is a person who uses ''mime'' (also called ''pantomime'' outside of Britain), the acting out of a story through body motions without the use of speech, as a the ...

type commonly in use is "application/x-blorb", and the

filename extension A filename extension, file name extension or file extension is a suffix to the name of a computer file (for example, .txt, .mp3, .exe) that indicates a characteristic of the file contents or its intended use. A filename extension is typically d ...

is ".blorb", or, for systems where filename extensions are limited to three characters, ".blb". Blorb files containing Z-code games may be named with the extension ".zblorb" or ".zlb"; or, for Glulx games, ".gblorb" or ".glb". These alternative extensions are intended to make it easier for interpreters to ascertain the type of game contained inside.

Formats supported in Blorb files

* Images: PNG and

JPEG JPEG ( , short for Joint Photographic Experts Group and sometimes retroactively referred to as JPEG 1) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degr ...

* Sound: AIFF, Ogg Vorbis * Music: MOD

References

External links

Blorb specification

Graham Nelson's page of Blorb resources
(Warning: the demo game ''The Spy Who Came In From The Garden'' on this page is actually an invalid Blorb file.)

Archive formats {{videogame-software-stub