Fluxus

http://www.pawfal.org/Software/fluxus/

   (define (tree d)
       (push)
       (rotate #(0 30 0))
       (translate #(0 0.6 0))
       (scale #(0.8 0.8 0.8))
       (push)
       (scale #(0.2 1 0.2))
       (draw_cube)
       (pop)
       (if (eq? 0 d)
           1
           (begin (rotate #(0 0 45))
           (tree (- d 1))
           (rotate #(0 0 -90))
           (tree (- d 1))))
       (pop))

    (show_axis 1)
    (clear)

    (colour #(0.5 0.5 0.5))
    (define (loop) (tree 8))

    (engine_callback "(loop)")