Fluent

Fluent is a localization system developed by Mozilla for natural-sounding translations. It is a monolingual format where each language has its own set of .ftl files.

Example:

# Simple message
hello = Hello World!

# Message with a variable
greeting = Hello { $name }!

# Message with attributes
login-input =
    .placeholder = email@example.com
    .aria-label = Login input
    .title = Login

Fluent is used by Firefox, Anki, and other projects. See the Fluent Syntax Guide for more details on the format.

Convert Fluent files to PO format using fluent2po.