[bonyt]

I assume this is because they’re published as plain text files. The HTML is styled to look the same as the plain text versions, including diagrams made assuming a fixed-width font.

https://tools.ietf.org/rfc/rfc793.txt

Plain ASCII text is a very compatible format, and probably will be for a very long time. For example, if you were to pipe this to a TCP socket on modern printer on port 9100 unchanged, it’ll likely print out roughly correct.

[crispyambulance]

OK, I see, but they provide three different formats: ASCII, PDF, and HTML.

If there's a zombie apocalypse and we end up raiding the computer history museum for 80 column line-printers, sure, it makes sense to select the ASCII version to make print outs so that we could rebuild the internet.

But for the HTML version? Come on! Freshen it up a bit.