Zi Corporation

Zi Corporation was a company that specialized in text input, mainly for cell phones. Nintendo used a few products from Zi Corporation for the Wii and DS. For the Wii, they used eZiText (predictive text). For the DS, they used Decuma (handwriting recognition) as used in games like Brain Age, Crosswords DS, Personal Trainer: Math, and for text input on DSi software. The way eZiText works on the Wii hasn't been figured out, nor how Decuma works. Zi Corporation was bought by Nuance Communications (notable for their "Dragon" software).

For the 3DS and possibly the Switch, a library is used called iWnn.