R. Buckminster Fuller; packing applicable things.
Steve Waterman's technique and the CCP; and:
My challenge to that technique, as to which packing closer packs in a sphere.
Special Case packing; 13 balls only, my exception to the Hales/Ferguson proof of Kepler's Conjecture,
and to the mistaken idea that R.B.Fuller's 13-ball VE-pack is tightest/densest.
Java applet on the web, "PackingMink" applet
My own packing program (not a ball packer; not a ball packer, NOT A BALL PACKER, although it can be easily used as one, and mistaken for one).
There are, surprisingly, quite a few additional pertinent resources on ball packing on the web.
I suggest you use Google, and keyword sets like "ball packing" "closest packing of balls" "sphere packing" (etc.).