Wikimedia Technical Operations/ICU announcement

Update to ICU Unicode library

Starting on 2 November 2023, we'll migrate the servers running the MediaWiki application servers to a new release of the ICU Unicode library (w:International Components for Unicode) (from version 63 to 67). This unblocks some future work on upgrading the servers to a new Operating System release and will also allow the use of improved internationalisation in the future. After this change, the wikis will be able to use features introduced by the new ICU release such as new collation definitions, and the developers will be able to use a more recent version of Unicode in MediaWiki.

This migration will cause some unavoidable temporary user-visible impact: The sorting of some category pages will be distorted – all pages which have been updated with the new software version will use the new sorting while untouched pages still use the old sorting. As such, we need to run a maintenance script to update the sorting for old entries.

The distortions may last from a few hours (on medium-sized wikis), up to a day (on the largest wikis), and a few days on English Wikipedia. The start-time will depend upon when the migration script reaches each wiki.

This affects 152 wikis (including some of the biggest Wikipedias). The detailed list and the task for the technical implementation is at T345561.

Thank you.