L20n.js has been deprecated and is no longer maintained. Please use Fluent, the successor to L20n developed by the same team at Mozilla. Fluent is a mature localization system currently used in Firefox and in many other Mozilla projects.
L20n is an opinionated localization library for the Web. It builds on top of Fluent which was designed to unleash the expressive power of the natural language.
L20n.js is a good choice for websites which want to offer a best-in-class translation experience for their users. L20n takes advantage of modern web technologies to offer a fast and lean localization of HTML and JavaScript.
Include the following code in the <head> section of your HTML:
<meta name="defaultLanguage" content="en-US">
<meta name="availableLanguages" content="de, en-US, fr, pl">
<link rel="localization" href="locales/myApp.{locale}.ftl">
<script defer src="dist/web/l20n.js"></script>Use the data-l10n-id attribute on an HTML element to mark it as localizable.
<p data-l10n-id="about"></p>That's it! L20n will set up a MutationObserver and will make sure the
element is localized even if the DOM changes. See docs/html for more
information.
It is also possible to use L20n programmatically, for instance in order to
localize dynamic content. The API is exposed under document.l10n. Refer to
the docs/ directory for more details.
L20n uses Project Fluent under the hood. FTL is a localization file format used for describing translation resources. FTL stands for Fluent Translation List.
FTL is designed to be simple to read, but at the same time allows to represent complex concepts from natural languages like gender, plurals, conjugations, and others.
hello-user = Hello, { $username }!
Read the Fluent Syntax Guide in order to learn more about the syntax. If you're a tool author you may be interested in the formal EBNF grammar.