Dreamships by Melissa Scott

A thought-provoking examination of the possibility of artificial intelligence. Reverdy Jian, a freelance "dreamspace" pilot based on Persephone (an arid world so hot the population lives underground), and her partners Imre Vaughn and "Red" take on a job flying a custom-made ship for the secretive Meredalia Mitexi. They're to search for Mitexi's lost brother Venya - an almost legendary designer of the near-sentient computer "constructs" that help human pilots navigate dreamspace - who vanished soon after his claim to have created a true artificial intelligence was suppressed by his corporate employer, Kagami Ltd. Aboard Mitexi's ship, Reverdy works with Manfred, Venya's custom construct, and she grows ever more convinced that Manfred might be sentient. When Reverdy learns that Mitexi plans to turn Manfred over to Kagami on their return, she decides she must protect the construct, though she risks her career and maybe her life.