Most people don’t use an operating system; they use software, which runs atop an underlying operating system. No matter how robust an operating system is, it’s useless without applications.

Many commercial operating systems include hundreds or thousands of small programs: games, desktop toys, and everything from fancy-looking clocks to disk scrubbers and web browsers. Most users never touch most of these programs, but the programs take up disk space (and possibly other resources) just the same. Every program drags along some amount of infrastructure, and all of this software can cause any number of problems.

Unlike many other operating systems, OpenBSD deliberately includes relatively little software in the default installation. You get exactly what you need to provide the infrastructure for software, and nothing more. While a traditional UNIX or Unix-like system includes compilers, games, and man pages, you don’t even need to install these when installing OpenBSD! Even if you install everything included in OpenBSD, it will have far less software than any commercial operating system. That’s because almost everything is considered an add-on package.

The advantage to this sparseness is that you know exactly what’s on the system, which simplifies debugging. A random shared library from a program you’ve never used won’t break your programs. The downside is that you need to think a bit to decide exactly what you do want to include, and you’ll need to install those programs. OpenBSD makes installing software as easy as possible through the ports and packages system, which is introduced in this chapter. But first, let’s take a look at building software.