An artificially constructed environment, whether a dome on the surface of a planet or moon, a rotating space habitat or artificial biosphere, a sealed environment in an asteroid belt, a worldship in deep space, or anywhere else, that enables, allows and encourages conditions suitable for sentient life, especially for civilization and sophont beings. Habitats are the foundation of galactic civilization.
Spaceweed - Text by Steve Bowers and John B A gengineered organism based on bladderwrack (Fucus vesiculosus) that has been modified so that it that can develop in Gas Giant rings, with a small (100-200 metres) bladder full of breathable air, and edible fruit and nuts growing on the inside. The bladders are loosely connected, with insulated flexible corridors between the bladders, and all the ice and rock of the rings incorporated into the spaceweed to avoid collision damage.