CSJ wrote on the debian-user mailing list:

For helping teach my kid to read I used emacs running emacspeak.
The robotic language, via the eflite speech synthesis server, was
sufficient to get the words' pronunciation across.  Type
"D-O-G-" in a buffer and you get the audio feedback "dog."
I used to set the xterm to the most massive font size available
(by adjusting the font and screen sizes) to make reading, or so I
assumed, easier for preschool eyes.