These are BDF fonts, a simple bitmap font-format that can be created by many font tools. Given that these are bitmap fonts, they will look good on very low resolution screens such as the LED displays.
Fonts in this directory (except tom-thumb.bdf) are public domain (see the README) and
help you to get started with the font support in the API or the text-util
from the utils/ directory.
Tom-Thumb.bdf is included in this directory under MIT license. Tom-thumb.bdf was created by @robey and originally published at https://robey.lag.net/2010/01/23/tiny-monospace-font.html