@pernia @meeper sexp is a shorthand for s expressions, the syntax (and ast/internal data representation, because in most lisps the two things are actually one and the same) of pretty much every lisp. parentheses matching is useful because large lisp programs accumulate a lot of parentheses and manually matching stuff like (((((()))))) is incredibly annoying (some non-emacs lisp editors go as far as providing full structure editing because of this, like what medley interlisp does). non block languages are languages where the script used for the letters needs to be kerned and combined at runtime, the letters don't fit in individual blocks like they do with most common scripts like latin or cyrillic. examples of such scripts would be devanagari (relevant to meeper), arabic (relevant to me for reasons), and then much weirder stuff like phags-pa.