Linux contains many of the same basic commands, attempts to follow the directory layout similarly, implements POSIX compliance where it makes sense, etc. But they're also very different, Linux package ...
FreeBSD and Slackware are both outstanding OSes. FreeBSD is more UNIX-like, while Slackware is more Linux-like. One is geared for servers, while the other is a bit more general. FreeBSD and Slackware.
Learn the ABCs of BSD.
FreeBSD is one of the most stable OSes on the planet. FreeBSD is also more challenging than Linux. You can download and install FreeBSD for free. I'm not gonna lie: I ...