gosh> (define M '((1 2 3 4) (5 6 7 8) (9 0 1 2) (3 4 5 6)))
M
gosh> (use srfi-1)
#<undef>
gosh> (apply zip M)
((1 5 9 3) (2 6 0 4) (3 7 1 5) (4 8 2 6))