Over the past quarter century, software exploits have evolved from rudimentary script-based attacks to sophisticated, multilayered processes orchestrated by cybercrime syndicates and nation-states. These exploits have shaped the way we build, distribute, and protect software, from development through quality assurance and public release. From the modest beginnings of the Internet in the late 1990s, when the world was coming “online” and becoming connected, security practitioners and threat actors raced to discover, disclose, and patch vulnerabilities. This chapter will trace the major milestones in software exploitation over the last 40 years, showing how vulnerabilities have grown into complex exploits and how the security community has adapted.