What are differences between the aforementioned distributions? Aside from the package management, what else is there? They all use the same file hierarchy, file systems and software. The only things I've read on this subject are trivial at best. Also, what is BSD and how does it differ from Linux?
I believe BSD is based on the Unix kernel, while Linux was written as a clone. BSD has slightly better memory management. They're all POSIX compliant though. Also, different distributions can have different kernels. Although they're all based on the plain vanilla linux kernel (www.kernel.org) they're often customized for the distribution with different features.
There are actually some pretty major differences between the distros you've mentioned. Probably the most important of these is the philosophy that drives each distro. Red Hat is a large, commercial, enterprise-oriented Linux vendor. Their RHEL platform aims to be a stable, mature and easily manageable platform, which is ubiquitous as the "Corporate Linux". As a result, their distro is not well suited for use as a home desktop OS, but makes a great server (you're connected to a Red Hat system as you read this). Each release has a long life-cycle of around 5 years. RHEL typically uses either yum or up2date as the package manager for its RPM-format packages. Debian, named after the creator of the distro Ian and his wife, Debora. Debian is a completely community-driven non-profit distro with no company behind it, yet it is one of the most prolific distros out there. It is highly flexible in its possible uses, has a staggering array of packages built for it, and has spawned many famous distros not the least of which is the Ubuntu family. The directory structure is slightly different than RHEL. Debian uses the excellent apt-get package manager for their deb-format packages. Slackware is the oldest surviving Linux distro. It is designed with an old-school Unix mindset, and as such as almost zero automation. While most distros use System V style startup scripts, Slackware uses BSD-like startup scripts. Slackware is a very hands-on distro, which is difficult to manage and update. However, since it has very little going on under the hood it is also considered a rock-solid distro. Slack's file structure is more like traditional Unices than other distros. Slackware uses the slapt-get package manager, modeled after Debian's apt-get. However, there is a major caveat between the two; slapt-get doesn't handle dependencies at all. Slackware uses plain, old tgz packages. BSD Unix is based on the BSD kernel. Linux is a Unix clone written to pick up where GNU/Hurd left off. Linux and BSD are both Posix compliant Unices, but there are some drastic differences between the two. See this thread near the bottom, "Which is Better, Linux or BSD?" for reference.
I've read this so many times before, and it always leaves me thinking: What happened to all the others? Surely Slackware wasn't the only *nix available back then? What were the alternatives and why did they fail or die out? I always like to try out different things, and I make no except with BSD. I've heard of OpenBSD and FreeBSD before. Which *BSD do you think is a good one to get started off with?
Slack wasn't even one of the first pre-packaged distros, in fact it grew out of another distro called SLS Linux. It is simply the oldest Linux distro which is still maintained in its original form under its original title and leadership. Other distros were absorbed, consolidated, or abandoned. However, it's all free software under the GNU license which means any substantial technological advancements in any one distro propagated to the others. In other words, the distros are still around in some form or another, or at least the benefits of those distros. We still have GNU/Linux. Depends on what you want to do with it. There are 3 main branches of the BSD project: FreeBSD, OpenBSD and NetBSD. None of them are what you'd call user-friendly, and none of them are extremely suitable for a desktop OS. If you're asking which BSD distro to use as a desktop OS, I'd say Darwin (i.e. MacOS X), not a BSD at all. But each BSD does have a specific focus. FreeBSD receives the majority of attention, being the more general BSD distro. NetBSD is the distro reputed to be able to run on any hardware, and is especially targeted towards embedded use. OpenBSD aims to be the most secure operating system on Earth. Each of these systems are designed to look, feel and act like a traditional UNIX platform. However, their performance, features and usability have been far surpassed by Linux, which has a much higher rate of development. On the other hand, the BSD kernel is considered more mature than the Linux kernel found in GNU distros, so it is preferred in some circles. Also, each are released under the BSD license, which means commercial entities can utilize the code without sharing their additions. This is attractive to corperations who are not interested in making their code public, but do not wish to write an OS from scratch either. On the other hand, the BSD license is probably the greatest reason that Linux has surpassed it in so many ways and why it will continue to do so over time. When one company adds features or improvements to BSD, nobody else benefits from their work in such a case. The GPL, on the other hand, guarantees that the source code and improvements to it will always be freely available -- which is why Linux enjoys such maturity at such a relatively young age.
Well if that's the case, I think i'll leave BSD alone for a while! I've never used OS X before, but I am through with proprietory Operating Systems anyway, so I'm in no hurry to try it.
I have, and it's quite pretty and much more functional than Windows. But it felt a bit bloated to me, and didn't handle multi-tasking as well as Linux (probably due to many factors not the least of which is their Mach micro-kernel). An environment like KDE seems much more functional to me than OS X. Overall, if somebody gave me a Mac I'd install Linux on it.
