[tpurves]

Well, lifeforms on earth are all pretty dependent on being water based, and water in the liquid state specifically. Maybe there is a possibility of exotic life based on some other types of chemistry and/or phases of matter. But the fact that earth happened to form in this particular goldilocks zone for water-based life is probably why that's the only life we can see for now.

[onestay42]

I have to mention Robert L. Forward’s Dragon Egg—it explores life on a white dwarf with nuclear reactions instead of chemical ones. Not the best book, IMHO, but a fun thought to entertain.