The item shown above is a macuahuitl, a type of primitive machete. It is made by taking a wooden board, carving out cavities, and embedding shards of obsidian (volcanic glass) in these cavities.
Atlatl - This compound spear/dart and thrower device was an important part of Aztec warfare. It was used by lighter infantry to provide "suppressing fire". To operate it, you would settle the end of the spear into the small knot on the curved end of the stick. Then, throw. It's simple, but effective.