@formatjs/intl-localematcher is a library that helps in selecting the best locale from a list of available locales based on the user's preferences. It is part of the FormatJS suite, which provides a set of tools for internationalizing JavaScript applications. The localematcher library is particularly useful when dealing with multiple locales and ensuring that the most appropriate one is chosen for formatting dates, numbers, and messages. This can enhance the user experience by providing content in a language and format that is familiar to the user.

While @formatjs/intl-localematcher offers a robust solution for locale matching, there are other libraries that provide related functionality. Here are a few alternatives:

• intl-messageformat is a library that allows developers to format messages in a locale-sensitive manner. It is particularly useful for applications that require dynamic message formatting, such as pluralization and gender-specific messages. By using intl-messageformat, developers can create messages that adapt to different languages and cultural contexts, making it an excellent choice for internationalized applications that need to present text in a user-friendly way.
• intl-relativeformat is another library that focuses on formatting relative time strings, such as "3 days ago" or "in 2 hours." It provides a way to display time in a way that is understandable and relevant to users, depending on their locale. This library is particularly useful for applications that need to present time-sensitive information in a clear and concise manner, enhancing the overall user experience.

To see how @formatjs/intl-localematcher compares with intl-messageformat and intl-relativeformat, check out the comparison: Comparing @formatjs/intl-localematcher vs intl-messageformat vs intl-relativeformat.