The colonists that populated the city on Gliese 581d had made a number of technological advancements that participated in the functioning of the colony.
The entire city was made up of Vardy, a type of microbot that interlocked in order to create solid and complete structures such as the buildings and the machines. They could easily break apart into swarms and attack anyone they perceived as a threat. They would envelop the target and could strip them of clothing and flesh in seconds, leaving nothing but bones behind. The Vardy also carried out daily tasks, such as pollinating the wheat fields that surrounded the city. The city was also equipped with Emojibot, an interface between the human colonists and the Vardy that carried out maintenance.
In the city humans communicated over long distances through a wireless network that was implanted directly into their ears and used their nervous systems as circuitry.