Software infrastructure companies build the technology that other software runs on — operating systems, databases, cloud platforms, networking software, middleware and security infrastructure. This creates a deeply embedded position in enterprise IT: when a company's core systems run on a particular database or cloud platform, replacing it is extraordinarily expensive and disruptive, resulting in switching costs that translate into pricing power and retention rates. The shift to cloud deployment has been transformational, converting large one-time licensing deals into predictable recurring subscription revenue while simultaneously expanding the total addressable market as smaller companies can now access enterprise-grade software without owning data centers. AI integration is rapidly becoming table stakes for competitiveness across all infrastructure software categories. For investors, infrastructure software companies with mission-critical products and demonstrated pricing power offer some of the most durable return profiles in technology, with the risk being competition from hyperscaler cloud providers who are expanding into software categories adjacent to their core infrastructure.