PC-BSD is a free, open-source operating system based on FreeBSD, that uses a unique style of package management that is more similar to the Windows install process.
PC-BSD has as its goals to be an easy to install and use desktop OS, which is built on the FreeBSD operating system. To accomplish this, it currently has a graphical installation, which will enable even UNIX novices to easily install and get it running. It will also come with KDE pre-built, so that the desktop can be used immediately. Currently in development is a graphical software installation program, which will make installing pre-built software as easy as other popular operating systems.
NetBSD is a free, secure, and highly portable, UNIX-like operating system available for many platforms, from 64-bit AlphaServers and desktop systems to handheld and embedded devices.
FreeBSD is a BSD operating system – the project includes a kernel, drivers, and utilities such as a shell.
FreeBSD is one of if not the most popular BSD, and serves as the basis for Apple’s Mac OS X operating system. FreeBSD is also quite commonly used on web servers, as it is known for reliability.