After the BeagleBone boots the kernel and allows you to log in, the system is ready to run the nonsystem software. This software runs in an unprivileged level, so bugs here are unlikely to crash the entire system. This software is typically what makes the BeagleBone specific to a task. Later on in this book, we will write this type of software as an exercise to familiarize ourselves with the BeagleBone. The line between the system software and nonsystem software can be unclear as most distribution includes a vast library of applications, either installed or easily installable with a few commands. The exact process depends on the distribution. For Angström users, this is done using the opkg command. For Debian users, this is done either by apt-get or dpkg just like on a desktop machine.

For a lot of BeagleBone users, the software library offered by distributions is commonly just a foundation to build upon. Depending on the intended task, additional software...