Happy birthday!
Pandoc is one of those things that I only recently discovered and totally fell in love with: I wrote a bunch of code in literate Haskell for work, so that I could have the logic right, and then ported it to JS to reduce the bus factor of the project. When I discovered pandoc I just ran it on my literate Haskell and the resulting PDF was so beautiful I had to print it out and tack it up on a cubicle wall, like a "this is what they pay me for" type of reminder.