Q# Pocket Guide

Foreword

When I first learned in the late ’90s of a different model of computation, I was instantly inspired and intrigued. How could there be another way for a computer to compute? How would that machine perform operations? What would it mean to program such a machine? My fascination led to my two-decade exploration of answers to such questions, an exploration that now is witness to a growing community of quantum developers, engineers, researchers, and enthusiasts, and an industry working to realize quantum advantage, the demonstration of an algorithm running on a quantum computer that gives a solution more powerful or faster than the best-known classical solution.

But the real impact comes when quantum advantage is practical—when we have solutions for practical problems of real-world interest, and those solutions have practical runtimes of less than a few weeks.

Practical is essential. As a computer scientist, I see the magic of quantum computers through the lens of a language, and through the ability to program, form a recipe, and efficiently express what we need the machine to do. The underlying instructions, operations, and programming model of a quantum computer are just different, and we need a different way to program it—a practical way that artfully captures the interplay between the highly hybrid nature of quantum algorithms and their quantum and classical needs.

And practicality is what comes to mind in reading Mariia’s new book. Over the last five years, Mariia, along ...