Quantum mechanical phenomena are manipulated in various ways by various commercial outfits. Rigetti, D-Wave, IBM, Intel, and Google, have achieved milestones toward a quantum computer which performs computations incapable of being performed by classical systems. Each company has a unique tack toward this goal. Rigetti is considered a “full-stack” operation; Google’s Bristlecone is a gate-based system employing superconductors; IBM…Read on for a quick synopsis of just what these leaders are up to and where they may end up.