It's no fun having a poster of a book if you can't read it, so I spent several hours learning about Middle English, and several days deciphering the whole thing (not counting the Latin note in the margin). Admittedly, I had help with the archaic words from Librarius (table of contents is in the left frame). I got good enough that I managed to read the first page of the knight's tale (image is high enough resolution that you can try reading it, too) without major problems (again not counting the Latin at the top of the page or on the side). I needed help with "whilom" (once upon a time), "Scithia" (the name of a kingdom of which I'd never heard), "solempnytee" (ceremony/fanfare), "woot" (willing), and "mencioun" (mention, but it's hard to read; see the last word on the sixth-to-last line) but I totally got the rest on my own. It's really fun reading and understanding old stuff like this!
I think there are 2 reasons why more people don't try this: the first is that it's no fun if you get a translation into modern English to read, since you miss all the interesting parts of the language, and the second is that if you read the original language, there are all these archaic words, spellings, and pronunciations that you're not used to (did you know that "plow" and "enough" used to rhyme? All words ending with 'ough' used to rhyme with plow, but you need to trace the etymology back to a time when yogh was a letter in the alphabet but neither g nor w were yet letters, and that gets us way off-topic). So, what we really want is a version of the Canterbury Tales written in Middle English but with modern footnotes explaining some of the words, and I'm having trouble finding such an edition. Edit: I mean something like Librarius but using the original alphabet, including thorns, several glyphs for s, and dashes over letters indicating trailing n's and such.
I decided to try this on my own. Surely this isn't hard to do in LaTeX: just grab all the characters you need, and go to town. but here's the weird thing: I can't find a dropped S anywhere. Several characters in the phonetics packages looked close, but none looked right (I guess no one uses computers to mimic 600 year old writing). I broadened my search to any font at all with both a dropped s and a normal one that I could import into LaTeX, since it didn't seem built in. What I really wanted was this font (note the 3 different glyphs for S), but I couldn't find it, either. I eventually happened upon Old English Bookhand, which was good enough. It wasn't too hard to install the font, and then I was up and going.
Things seemed to work, so I used the lettrine package to make a dropped capital for the start and made the first paragraph. Unfortunately, the results were bad enough that I never bothered getting much further past a "Hello, world!" stage. The details are all wrong! The dropped s should be higher up. There should be more space after l's. The 'ri' digraph (using a dropped r) looks just like an 'su' digraph (again, using a dropped s), which totally changes the meaning of "myghty and riche"! So, there should really be a ligature for 'ri's to do it right. I was hoping to get the spacing identical to the original, but the fourth line is way too long, so I'd have to give up on that. and if I had my druthers, the yogh would really be a g, and the u and w would be much fancier. So, this font wasn't working out.
"Surely," I thought, "I can fix these problems! I can use METAFONT to create an Ellesmere-like font to my liking, and use that." This has the added bonus that I can illuminate my manuscript as well. Unfortunately, I don't yet know METAFONT. I went through several crap tutorials that read as though they were created by high schoolers, and finally just hunkered down with The METAFONTbook. In the preface, Knuth mentions that "very few people" have the skills needed to make a good font, which wasn't very encouraging. I'm now 35 pages into it, and I still know approximately nothing about how to make fonts. but I've learned all sorts of interesting things about Bezier curves and the algorithms used to draw them, which are actually fairly clever if a bit esoteric.
This story isn't really going anywhere (I'm probably going to give up on writing my own font, let alone typesetting the Canterbury Tales), but I thought it was interesting how one thing lead to another in this chain of events, and how they spanned 600 years of history (900 years if you count the etymology of rhyming 'ough' words, or 2400 years if you count the description of Theseus in the knight's tale) and crossed several fields of study, from literature to history to etymology, computer science, and mathematics. Everything in the world is connected, and it's all way more complicated than I'd expect!