Spore uses procedural textures to give players almost unlimited scope in painting their creatures, and groundbreaking animation technology to determine how they move, hunt, fight, mate, and even dance. Less well-publicised is Spore’s procedural sound technology. Unique creatures are given voice by algorithms that take into account the creature’s size, age, biology, structure, and behaviour. Even more amazing is its procedural score. Prog rocker Brian Eno has co-operated with Maxis to write and record small pieces of music for the game. According to in-game events, these elements will be manipulated procedurally to make non-looping dynamic music that suits the action be it a fight, a hunt, or some quiet space exploration.

The Age Blogs has a great writeup on the technology of Spore.  They go in-depth on how Spore will be the best game so far in terms of procedurally generated content.  By that, it refers to any game content (used to be created by the studio’s programmers, animators, designers, and artists) created on the fly by use users.  They also take a look back at other games that started this process starting with the game Elite in 1984.