UTW 2026

Tutorial
Keyboards ICU/CLDR

How to build a LDML-format keyboard

Marc Durdin, Andrew Glass

on  Weds, 9:30in  Creativity Station (Room 109)for  90min on  Weds, 11:30in  Creativity Station (Room 109)for  90min

Part 1 - overview, character repertoire, devices, layouts, and distribution

In this session, we will walk through the Unicode Technical Standard #35, part 7 - LDML keyboards. We will explore the file format, and how to design a basic keyboard. We’ll introduce tools such as Keyman Developer, explain multi-device support, and discuss how to test, share, and submit the keyboard to CLDR. At the end of this session, you will have gained the skills needed to create and submit simple keyboard layouts to CLDR.

Part 2 - gestures, transforms, reorders, backspace

Building on the previous session, we’ll dive into building advanced keyboards that leverage the full capabilities of the LDML keyboard specification — including gestures for touch devices, transforms to streamline the text input experience, reorders to canonically ordered text at input time, and how to deal with backspace, the most difficult key on the keyboard. By the end of this session, you will be able to create powerful, intuitive keyboard layouts that enable end users to input text in their language with confidence and ease.

 Overview  Program