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
The texguire-27.bdf font was created using the otf2bdf tool from the TeX Gyre font.
otf2bdf -v -o texgyre-27.bdf -r 72 -p 27 texgyreadventor-regular.otf
Fonts are in a human readable and editbable *.bdf
format, but unless you
like reading and writing pixels in hex, generating them is probably easier :)
You can use any font-editor to generate a BDF font or use the conversion tool otf2bdf to create one from some other font format.
Here is an example how you could create a 30pixel high BDF font from some TrueType font:
otf2bdf -v -o myfont.bdf -r 72 -p 30 /path/to/font-Bold.ttf