Steel Cables aka Tensegrity or Tensional Integrity
This is not a unique frame build material because wires or cables only work under tension. So this bike requires at least two beams of some other non-compressible material, in the form of a main beam and a seat post.
Earlier:
More modern construction with only one wire:
Advantages
Less frontal area, lower wind resistance and therefore more aero.
Theoretically lighter than tubes.
Disadvantages
Not actually lighter than tubes, because the main beam has to be beefier, and steel cable is not light in the first place.
Cheesecutter - In the event of an accident, the topwire/toptube would do significantly more focused damage based on its smaller size. Like those taunt wires used to cut fancy cheese. cringe
Flex - these bikes were excessively compliant in the horizontal direction.
Future
Some development has been done with kevlar cables and carbon fibre main beams.