"The Beginning and the End: The Meaning of Life in a Cosmological Perspective" by Clément Vidal. Technically this is just a "PhD thesis preprint" but it's over 350 pages long. A sprawling manuscript in which the author devises a meaning-of-life philosophy based on systems theory, the conquest of the universe by superintelligence, and other ingredients. The discussions of physics and cosmology are unduly dominated by certain "alternative" theories and could have benefited by orthodox criticism, and no doubt much of the rest should be read skeptically too, but overall, this is worth knowing about, if you're into transhuman cosmo-ethics.