Apart from the ones already mentioned, there is https://pad.riseup.net/ (Etherpad Lite) https://pads.ccc.de/ (Etherpad)
Riseup Pads are also available as Tor hidden service: https://ttbmov2dezfs2fln.onion/ -- Moritz Bartl https://www.torservers.net/ -- Unsubscribe, change to digest, or change password at: https://mailman.stanford.edu/mailman/listinfo/liberationtech
