Blorb Blorb File extension : .blb MIME type : application/x-blorb Developed by : Andrew Plotkin Type of format : Package format Container for : PNG , JPEG , AIFF , MOD Extended from : Interchange File Format Extended to : IFRS 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 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 , 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 code of the game itself . This allows authors of modern games to shi p 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 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 interactive fiction interpreters , including Nitfol and Glulx . The Blorb format continues the tradition of naming interactive fiction tools after spells in Infocom 's Enchanter trilogy . Blorb was a spell to bind objects into boxes . Blorb is an IFF format , with FORM IFRS . The MIME type commonly in use is `` application/x-blorb '' , and the filename extension is `` .blb '' . Formats supported in Blorb files Images : PNG and JPEG Sound : AIFF Music : MOD 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 . ) Some tools for working with Blorb files Blorb files for Infocom games Categories : Archive formats Blorb .blb application/x-blorb Andrew Plotkin Package format PNG , JPEG , AIFF , MOD Interchange File Format IFRS 