This book covers several futuristic computing technologies like quantum computing, quantum-dot cellular automata, DNA computing, and optical computing. In turn, it explains them using examples and tutorials on a CAD tool that can help beginners get a head start in QCA layout design. It discusses research on the design of circuits in quantum-dot cellular automata (QCA) with the objectives of obtaining low-complexity, robust designs for various arithmetic operations. The book also investigates the systematic reduction of majority logic in the realization of multi-bit adders, dividers, ALUs, and memory.