this is great. at the last stupid hackathon in SF I worked on a font for cats with over 7 million ligatures (every fourth letter, it turns what you just typed into "meow.")[1] it was tricky to figure out how to push ranges and named lookups to the limit, and there doesn't seem to be any getting around the speed issue, but there's a lot of underlying font tech to have fun with :)
Love it! Also, "Fun fact: the well known ampersand, &, was originally a ligature for “et”, meaning “and” in Latin," completely amazed me. I never knew.
It's basically a 't' with the cross-bar curled over to form something like an 'e'.
I don't have any citations, but I'm pretty sure most of this evolution pre-dated the concept of "fonts," when all documents were handwritten manuscripts.
The ℞ (Rx) symbol used for prescriptions started out as a ligature for Rt — an abbreviation form "receipt", the same root from which we get the modern English word "recipe".
The story I heard is that it's an abbreviation for the Latin word "recipe" ("take"). Apparently it was a convention in handwritten manuscripts to use a dash to indicate abbreviations where letters have been omitted, hence a dashed R in this case.
It's actually more complex than simply adding a slash to indicate you're omitting letters. Both the position of the mark and the kind of mark you make indicate exactly what letters are being omitted. It's a medieval form of shorthand, except unlike modern shorthand, it appears in all kinds of books. Back when every copy of every book had to be written by hand, it was acceptable to take shortcuts.
Oh, and the really cool part is that scribal abbreviations were the banner feature of Unicode 5.1 (you can thank MUFI for putting the work into getting these into Unicode), so you can actually use them in text now!
I have no definitive source, my understanding came from a conversation with a typographer 10+ years ago.
A little digging around suggests that receipt was in use in English (meaning list of ingredients) both in the culinary and pharmaceutical sense from the 14th century, and recipe was introduced a couple of hundred years later. Both, of course, from the same Latin root.
That's what I liked about this as well; not like you'd actually use the font, but in the process, it walks through how ligatures work in modern font formats.
Behad Esfahbod is, quite frankly, a font and script genius. When I was delving into understanding LibreOffice's font and layout mess (which is getting better, btw) I kept seeing his name and work in harfbuzz.
The world, I feel, owes this man a great debt and I fear he is one of the great unsung open source heroes we seem to hear so little about!
Immediately looked to see whether the substitution language is Turing complete. Luckily, it appears not.
Seems like you could do some very quirky animation using ligatures. For example-- imagine that the ligature for "Im" tilts the "I" toward the "m". Then the ligature for "Imm" tilts the "I" further, and so on, until I type the complete word "Immediately" and the "I" has drifted down below the "y" character.
Repeat this drift for each subsequent letter typed, slowly increasing the amount of displacement for the letters in the ligatures. Then, by the time I've finished typing this comment, all the letters would end up piled up in the corner of this textarea. :)
I was experimenting with this concept in 2012, and I think this is still relevant today. I wanted to make a web font with ligatures that replaced popular company names with their actual company logos.
It ended up being way too much work, and it isn't monetizeable due to the copyrighted nature of many logos.
1. https://github.com/jpt/meow