Interfaces between dimensions of a solution. Perhaps it leads to a real physical interface, but the solutions to (n-dimensional) trees implemented as a cave like system which can be navigated , demonstrates the path and choices to many solutions. The dimensions are sometimes real and sometimes logical or virtual. Markings on the interface indicate what dimension is connected, direction and the distance scale of change. These dimensions can indicate dimensions of any property as well as space and time or even changes in genotype to phenotype sequences.
Sometimes the interfaces are used by AI ant objects to travel dimensions of choices.
ADDED: And other times, unexpected things happen when many technologies combine.