ICU4X provides components enabling wide range of software internationalization. It draws deeply from the experience of ICU4C/J, ECMA-402 and relies on data from the CLDR project.

ICU4X is fully implemented in the Rust programming language.

The design goals of ICU4X are:

• Small and modular code
• Pluggable locale data
• Availability and ease of use in multiple programming languages
• Written by internationalization experts to encourage best practices

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An example ICU4X powered application in Rust may look like this:

Cargo.toml:

[dependencies]
icu = "2.0.0"

src/main.rs:

use icu::calendar::Date;
use icu::datetime::{DateTimeFormatter, fieldsets::YMD};
use icu::locale::locale;

let dtf = DateTimeFormatter::try_new(
    locale!("es").into(),
    YMD::long()
)
.expect("locale should be present in compiled data");

let date = Date::try_new_iso(2020, 9, 12).expect("date should be valid");

let formatted_date = dtf.format(&date).to_string();
assert_eq!(
    formatted_date,
    "12 de septiembre de 2020"
);

ICU4X is developed by the ICU4X Technical Committee (ICU4X-TC) in the Unicode Consortium. The ICU4X-TC leads strategy and development of internationalization solutions for modern platforms and ecosystems, including client-side and resource-constrained environments. See unicode.org for more information on our governance.

ICU4X-TC convenes approximately once per quarter in advance of ICU4X releases. Most work in the interim takes place in the ICU4X Working Group (ICU4X WG), which makes technical recommendations, lands them in the repository, and records them in CHANGELOG.md. The recommendations of ICU4X WG are subject to approval by the ICU4X-TC.

Please subscribe to this repository to participate in discussions. If you want to contribute, see our contributing.md.

For the full charter, including answers to frequently asked questions, see charter.md.

ICU4X is a new project whose objective is to solve the needs of clients who wish to provide client-side internationalization for their products in resource-constrained environments.

ICU4X, or "ICU for X", will be built from the start with several key design constraints:

1. Small and modular code.
2. Pluggable locale data.
3. Availability and ease of use in multiple programming languages.
4. Written by internationalization experts to encourage best practices.

ICU4X will provide an ECMA-402-compatible API surface in the target client-side platforms, including the web platform, iOS, Android, WearOS, WatchOS, Flutter, and Fuchsia, supported in programming languages including Rust, JavaScript, Objective-C, Java, Dart, and C++.

Copyright © 2020-2024 Unicode, Inc. Unicode and the Unicode Logo are registered trademarks of Unicode, Inc. in the United States and other countries.

The project is released under LICENSE, the free and open-source Unicode License, which is based on the well-known MIT license, with the primary difference being that the Unicode License expressly covers data and data files, as well as code. For further information please see The Unicode Consortium Intellectual Property, Licensing, and Technical Contribution Policies.

A CLA is required to contribute to this project - please refer to the CONTRIBUTING.md file (or start a Pull Request) for more information.

The contents of this repository are governed by the Unicode Terms of Use.