
Linux is by far the most successful open-source operating system in use. It isn’t the only one by a
long shot, however. FreeBSD, OpenBSD, and NetBSD are other successful open-source platforms, and
Darwin, the BSD-based operating system that lies underneath MacOS X, is open source as well! Just
because Linux is open source doesn’t mean that nobody can make a profit off it. Companies and
organizations such as Debian, Red Hat, and Yellow Dog all sell or give away their own distributions of
Linux: a base Linux kernel bundled with usability tools, documentation, software to make installation
easier, and technical support.
Software designed for one Linux ...