Also known as lightships, nullships are peripatetic virchworlds with a 'crew' of virtual sophonts wandering the Lightways. The Nullship represents a stable environment for a virtual sophont to inhabit, and as a base for interactions with the local cybercosm. Each Nullship is a self-contained virtual environment which exists only as data, and this environment is transmitted from location to location as a first step before transmitting the mindstates of the crew and associated passengers. On arrival the passengers and crew can be activated in virtual bodies inside this familiar environment, which becomes their home and a convenient place to meet, negotiate with, and entertain the local sophonts.
Sometimes the Nullship takes the form of a relatively realistic spacecraft, and will interact with the local planetary net in the same way that a real-life vessel might do. In other cases the Nullship is a completely fantastical vessel, sometimes taking forms that would not be possible in the physical world. On occasion the Nullship may take the form of a large ocean-going ship on a virtual ocean, or other inhabitable structure.
Nullships may spend days to years in a Lightway Inn before travelling onwards. In the Outer Volumes, especially, the arrival of a nullship can be a significant event. Nullships can be carried beyond the Lightway network inside dataships, or even as cargo inside a peripatetic ISO.