Node.js can link against an ICU build already installed on the system. In fact, most Linux distributions already come with ICU installed, and this option would make it possible to reuse the same set of data used by other components in the OS.

    Functionalities that only require the ICU library itself, such as [String.prototype.normalize()][] and the [WHATWG URL parser][], are fully supported under system-icu. Features that require ICU locale data in addition, such as [Intl.DateTimeFormat][] may be fully or partially supported, depending on the completeness of the ICU data installed on the system.