We identify "life" with the capability of self-replication plus some other features. In other conditions, for instance on other planets, it could be possible for self-replication to happen in a way different from the RNA/DNA-based one.

I remember stumbling, years ago, on research and papers that studied this kind of possibility. But I'm having a hard time finding the old references or new ones.

Do you have interesting papers and research material to share about this? Thank you!