XPInstall (Cross-Platform Install) is a technology used by the

Mozilla Application Suite The Mozilla Application Suite (originally known as Mozilla, marketed as the Mozilla Suite) is a discontinued cross-platform integrated Internet suite. Its development was initiated by Netscape Communications Corporation, before their acquisition ...

, SeaMonkey,

Mozilla Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current a ...

Mozilla Thunderbird Mozilla Thunderbird is a free and open-source cross-platform email client, personal information manager, news client, RSS and chat client developed by the Mozilla Foundation and operated by subsidiary MZLA Technologies Corporation. The projec ...

and other XUL-based applications for installing Mozilla extensions that add functionality to the main application. A XPI (pronounced "zippy" and derived from XPInstall) installer module is a

ZIP Zip, Zips or ZIP may refer to: Common uses * ZIP Code, USPS postal code * Zipper or zip, clothing fastener Science and technology Computing * ZIP (file format), a compressed archive file format ** zip, a command-line program from Info-ZIP * Zi ...

file that contains an install script or a manifest at the root of the file, and a number of data files. In Mozilla, Firefox before 0.7, and before 0.5, the package contained a

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 Website, websites use JavaScript on the Client (computing), client side ...

install script (install.js) with some directives for actions to take during an install, including adding files and directories, removing old or obsolete files and directories, executing command line tools, etc. In middle-old Firefox and Thunderbird versions, the install script has been replaced by a

chrome Chrome may refer to: Materials * Chrome plating, a process of surfacing with chromium * Chrome alum, a chemical used in mordanting and photographic film Computing * Google Chrome, a web browser developed by Google ** ChromeOS, a Google Chrome- ...

manifest and a RDF file (install.rdf). Since Firefox version 45, the only mandatory file is manifest.

json JSON (JavaScript Object Notation, pronounced ; also ) is an open standard file format and data interchange format that uses human-readable text to store and transmit data objects consisting of attribute–value pairs and arrays (or other s ...

. Since Firefox 1.0, XPIs from sites other than Mozilla Add-ons are blocked by default. This was an attempt to prevent malicious programs, like

computer virus A computer virus is a type of computer program that, when executed, replicates itself by modifying other computer programs and inserting its own code. If this replication succeeds, the affected areas are then said to be "infected" with a compu ...

es, Trojans and

spyware Spyware (a portmanteau for spying software) is software with malicious behaviour that aims to gather information about a person or organization and send it to another entity in a way that harms the user—for example, by violating their privac ...

, from being installed by novice users. While it is possible to put a site into the

whitelist A whitelist, allowlist, or passlist is a mechanism which explicitly allows some identified entities to access a particular privilege, service, mobility, or recognition i.e. it is a list of things allowed when everything is denied by default. It is ...

that limits sites which can install XPIs, malicious sites cannot install extensions in the background (without human intervention). This is because a confirmation dialog needs to be answered for every single installation of an extension. However, users are still advised to install extensions from trusted sources only.

Applications with built-in support for XPInstall

Web browsers

* Flock * SeaMonkey * Netscape Browser

Other applications

* Nvu (web authoring application) *

Songbird A songbird is a bird belonging to the suborder Passeri of the perching birds ( Passeriformes). Another name that is sometimes seen as the scientific or vernacular name is Oscines, from Latin ''oscen'', "songbird". The Passeriformes contains 50 ...

(media player and organiser) * Mozilla Sunbird *

Google Gears Gears, formerly Google Gears, is discontinued utility software offered by Google to create more powerful web apps by adding offline storage and other additional features to web browsers. Released under the BSD license, Gears is free and open-sour ...

External links

* * * {{DEFAULTSORT:Xpinstall Mozilla