The best programming font I have come across so far is Terminus. I use it for everything except printed documents.

Unfortunately, there are at least the following shortcomings of Terminus:

• Characters 0 and 8 are hard to distinguish. It does not annoy me much in practice, but a better font might solve this :)

• As Terminus is a bitmap font, some programs do not want to display it. There is a Terminus TTF version, but it lacks the clarity of the proper bitmap Terminus unless you happen to hit exactly the right font size and have all the modern things (hinting, antialiasing, etc.) turned off!

Hence, from time to time, there is need for some TTF/vector font instead. Given that there are tons of other programming fonts it should not be hard to find a proper substitute except it seems incredibly hard to get the details right. Maybe I am just too much used to Terminus.

The screenshots on this page were created using theme Night, font size 16 and the C code from https://github.com/m7a/bo-z80-ti84plus-trtotp/blob/master/trtotp.c on the following page: https://www.programmingfonts.org. The exception is Monoid which has been tested at font size 15 because 16 was very wide.