The core idea of the meetup was to share knowledge by pair programming. I know Vim and my partner, Gianfranco, certainly know functional programming. Together we hacked together a Haskell program in Vim; simple enough for me to get the hang of the language but varied enough so Gianfranco could learn some Vim tricks.
We did so ping pong style, where one of us would start by writing a test and the other would make that test pass, before writing a test himself. I really liked that approach.
And I definitely hope to see more of these events!