  This technical report describes our deep internationalization program for
Gboard, the Google Keyboard. Today, Gboard supports 900+ language varieties
across 70+ writing systems, and this report describes how and why we have been
adding support for hundreds of language varieties from around the globe. Many
languages of the world are increasingly used in writing on an everyday basis,
and we describe the trends we see. We cover technological and logistical
challenges in scaling up a language technology product like Gboard to hundreds
of language varieties, and describe how we built systems and processes to
operate at scale. Finally, we summarize the key take-aways from user studies we
ran with speakers of hundreds of languages from around the world.
