Commonly used words

From MozillaZine Knowledge Base
Jump to navigationJump to search

These are commonly used words and acronyms throughout the Mozilla Community.


These acronyms are commonly used in the IRC chat rooms and in the forums.

Web places

Products and components products

Components and technologies

  • JS means JavaScript, a lightweight browser-based scripting language created by Netscape many moons ago
  • XUL means XML User Interface Language, a dialect of XML (Extensible Markup Language) for creating user interfaces
  • XPCOM means Cross Platform Component Object Model, a Mozilla technology that is somewhat similar to Microsoft's COM. **deCOMtamination is the process of removing unnecessary uses of XPCOM from the Mozilla codebase in order to improve performance.

See also Development resources.



  • RFE means Request For Enhancement - a feature request
  • URL stands for Uniform Resource Locator. It is the address of a page or file on the web.
  • UNCO means Unconfirmed, a bug that can't be or hasn't been reproduced by testers
  • WFM means WORKSFORME, which is Bugzilla and forum speak for 'Not broken for me'


And the following is a list of acronyms you will often come across when you're in the Mozilla IRC channels ( - these are in addition to the ones listed above:

  • AFAIK: As far as I know
  • ATM: At the moment
  • BRB: Be right back
  • IIRC: If I remember/recall correctly
  • NP: No problem

Browser related terms

Here are a few words used commonly when talking about any browser:

Location bar (Address/URL bar)
The space at the top of the browser window which shows the current web page that is being viewed. If you type the address of a new web page there and press enter, you will be taken you to the new page.
Status bar
The bar on the bottom of the window that displays various statistics, such as page loading progress, errors, and messages.
The icon (usually in the upper right corner of the web browser) that animates when the browser is loading a page. In SeaMonkey, and in older versions of Firefox, clicking on this icon opens the browser's home page (for example, in SeaMonkey: See also: Throbber URL

User-Agent String

Gibberish like these:

  • Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.6) Gecko/20040206 Firefox/0.8
  • Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040327 Firefox/0.8

... are Mozilla application's UA (user agent) string. It specifies exactly which version you're using, which can be useful in tracking down bugs and explaining odd behaviour. It can be found in the application's Help > About dialogue, or the about: page.

The important parts are:

  • Operating system ("Windows NT 5.1" or "Linux i686")
  • The Build Identifier ("20040206" or "20040327".) The first four digits represent the year of the build, the next two represent the month, and the next two the day. Sometimes there are 2 additional digits to represent the hour.
  • Product name (Firefox)
  • Release version (0.8)

Other Jargon

(WIP section for bug 202689)

The keyword used to label Firefox branches. Aviary is sometimes used to refer to Firefox, Thunderbird, and other Toolkit applications.
The codename for the layout engine in Mozilla browsers.
NGLayout (Next-Generation Layout)
The project codename for the layout engine.
GRE (Gecko Runtime Engine)
MRE (Mozilla Runtime Engine)
Former name for GRE.
A fix to the bug.
Review granted to a patch. "r+=Robin" (or simply r=Robin) would mean the patch is okay'ed by Robin, and conversely "r-" would mean the patch is denied. r, sr, and a are commonly used in Bugzilla and also in CVS check-in comments
Approval (for patch check-in). "a=Robin" would mean a patch is approved for check-in by Robin".
A (as small as possible) demonstration of the bug that testers and patchers could test by.
The project name for the official Mozilla Suite. SeaMonkey is also the project name for the continuation of the Mozilla Suite by the SeaMonkey council.
The Mozilla Foundation.
Commonly put in the Status Whiteboard of a bug, meaning "I believe this is a duplicate bug, but I cannot find it at the moment or did not look for it."
Bugzilla privilege which allows the user to change almost all fields in a bug.
Bugzilla privilege which allows the user to confirm a bug.
nightly build
Builds that are generated on a daily basis which contain fixes to bugs.
A release.
release candidate (RC)
A candidate for the next major release.
A beta build of the next release.
An alpha build of the next release.
Unnecessary comments in bug reports. Like "me too", etc. Also e-mail messages sent by Bugzilla mailer.
tinderbox builds
Builds that are automatically generated from the tinderbox on an hourly basis. These are updated more frequently than nightly builds.

Other Resources

Acronym Finder is a very good resource for finding out what some Mozilla-related acronyms stand for.

The Mozilla Jargon file, Bugzilla code definitions page, and Bugzilla keyword list have many definitions for words used by Mozilla hackers.