Diaspora

Citizens as software, running inside polises; robot and flesh branches by choice.

Mathematics, for pleasure, at whatever subjective clock rate suits. Some run slow to let centuries pass, some run fast, some fork themselves to pursue two interests at once.

Play as vocation — Work becomes hobby, and the serious people go looking for risk on purpose.

The most rigorous treatment of what minds do when substrate stops constraining them. Also the hardest reading on this list.