As someone pointed out in that thread, the original version of the "Dragon Book" was out in 1977, making it 45 years old:

https://twitter.com/vinodg/status/1497632140254609408

I used it in a compiler class in college in 1980, and it was already known as the "Dragon Book" back then.

You can still buy a used copy on Amazon:

https://www.amazon.com/Principles-Compiler-Addison-Wesley-in...