The worldwide landscape for raising firm capital from Initial Public Offerings (IPOs) has significantly evolved over the last few decades. This introductory chapter reviews more recent research on initial public offerings. The Oxford Handbook of IPOs comprises twenty-nine chapters from authors around the world. The chapters describe the economics of going public, short- and long-term performance of IPOs, regulation of IPOs, IPOs versus acquisitions, reverse mergers, special purpose acquisition companies, service providers including investment banks and auditors, venture capital funds, international differences in IPOs, and crowdfunding. The Introduction summarizes the chapters that appear in the Handbook and highlight research trends on topic.