MessageFormat Working Group is pleased to announce that it has released a
Technical Preview implementation of the current state of the MessageFormat 2

in ICU4J in the recent ICU 72 release. The Working Group
has been working on a specification for a successor to ICU MessageFormat, which
has been an industry staple for internationalized software for more than two

Owing to the prevalence of MessageFormat not just as an API for
software, but also given its syntax serving as a de facto serialization format
for the localized messages sent to the API, the Working Group has put careful
consideration into

interchange and interoperability
. Some

of the new specification include promoting best practices for
internationalization, including compatibility with localization industry
supported XLIFF. Another goal includes a definition of the data model of
the API input separate from the syntax to allow for multiple compliant syntaxes
to be compatible. Similarly, the specification includes a registry of
interfaces for dependent formatting functions, in order to cleanly separate
implementation from specification, allowing users to specify custom formatting
functions and plug in their own implementations.

MessageFormat 2 builds on top of the experience from using and
maintaining ICU MessageFormat and a number of other localization systems and
workflows. It improves the placeholder syntax, improves escaping rules inside
the translatable content, replaces nested selectors with top-level multiple
selectors, and allows the use of custom formatters.

For example:

match {$photoCount :number} {$userGender :equals}
when 1 masculine {{$userName} added a new photo to his album.}
when 1 feminine {{$userName} added a new photo to her album.}
when 1 * {{$userName} added a new photo to their album.}
when * masculine {{$userName} added {$photoCount} photos to his album.}
when * feminine {{$userName} added {$photoCount} photos to her album.}
when * * {{$userName} added {$photoCount} photos to their album.}

More examples and the formal definition of the grammar can be found
in the
specification draft

We invite you all to try the Tech Preview available now in ICU4J
and provide us any and all feedback. Similarly, please note that the
MessageFormat 2 is still a work in progress, and therefore we rely on your
questions, suggestions, and issues to critically inform how we iterate on the
specification. Real world experience will allow us to address potential
shortcomings in the ways that MessageFormat 2 will get used in practice.

For information about using the Tech Preview, refer to the

API docs
, ICU 72 download page,
and the ICU4J User

To leave feedback about MessageFormat 2 (specification, syntax, etc.) or the
Tech Preview implementation, please visit the working group’s repository at
, where you can open a new
Discussion topic or file a new Issue.

Over 144,000 characters are available for adoption
to help the Unicode Consortium’s work on digitally disadvantaged languages