All the BSDs emerged from the BSD (Berkeley Standard Distribution) Unix tradition. All offer a generally monolithic "cathedral" style development approach to the OS as a whole (kernel, libraries, utilities, applications), rather than the more piecemeal "bazaar" style favored by most GNU/Linux distros.
The BSDs in general have fragmented rather less than GNU/Linux development has, though the latter have also captured a far larger deployment base, by most estimates. Adding Android to the mix, Linux competes with any end-user platform. BSD is also the root of many proprietary Unix variants, an intentional characteristic of its licensing model.
FreeBSD in general is aimed at the server and desktop niche with a particular expertise in networking. FreeBSD originated in the "UNIX Wars" of the early 1990s during which AT&T attempted to assert its trademark and copyright over the increasingly popular BSD and 386BSD ("1-800-ITS-UNIX") operating systems. That case was a landmark, with AT&T substantially failing to assert its claims. The ruling was largely sealed, but much of it was subsequently unsealed during the SCO v. IBM trial, greatly damaging SCO's case (also based on copyright claims over UNIX). Arguably the uncertainty generated by the lawsuit provided a toehold for Linux to gain in early critical popularity, though the openness of its development model also likely contributed to this.
NetBSD forked from FreeBSD with the aim of providing as broad a range of hardware support as possible, though arguably some GNU/Linux distros such as Debian have trumped it.
OpenBSD forked from NetBSD with the aim of providing a very high security platform. OpenBSD lags in many high-performance and scalability characteristics, but offers an exceptionally robust security profile and default deployment security characteristics. The project website has long bragged about its security record (presently "Only two remote holes in the default install, in a heck of a long time!"). Notable OpenBSD projects include the pf firewall suite and OpenSSH. There's also been a project to remove all GPL'd code from the OpenBSD release, though attempts by the original pf author to write a specific exclusion into his license for use in GPLd projects (which the BSD license otherwise allows) resulted in that codebase being removed and the suite rewritten from the ground up. Theo's ideological purity is different from Stallman's in bent, but no less strong in my opinion.
There are a few even smaller distros (notably DragonflyBSD), I'm less familiar with these.
Underlying all of the BSDs is the BSD license, which is "permissive", requiring only that the license text be included in derivative works -- those works themselves need not carry source distribution obligations as most of the GNU licenses (GPL, LGPL, GPLV2, GPLV3) do. The result (intentional) is that the BSDs are used in a wide range of proprietary products, not merely dedicated servers. I've found BSD in routers, load balancers, printers, fax machines, settops, and other devices, usually identifiable by nmap fingerprinting scans.
All offer a generally monolithic "cathedral" style development approach to the OS as a whole (kernel, libraries, utilities, applications), rather than the more piecemeal "bazaar" style favored by most GNU/Linux distros.
This has gotten a bit less true, though not entirely. The classic Unix model really did develop the entire system in the unified development model: kernel, userland, servers, major application software, etc. You could then also install third-party packages for specific application software (e.g. Matlab), but it wasn't the norm, and didn't handle core functionality.
But some components have gotten to be big enough that they're entire projects in themselves, usually cross-platform and not integrated with any one OS's development. Some of these are adopted into the BSD core respositories and customized so they form part of the integrated offering, but a number are just left in ports and run mostly unmodified. Webserving is one example: when used as a webserver, the BSDs, just like Linux, depend for a core part of the functionality on Apache or nginx. A few of the commercial unixes do follow the more traditional "everything included" model, e.g. Oracle and IBM have in-house customized versions of Apache as Oracle HTTP Server and IBM HTTP Server respectively. But the free BSDs generally run this kind of software un- or very lightly modified. The compiler is another example; the BSDs all ship basically a stock GCC or LLVM, rather than having an in-house compiler developed with the system, like the old commercial Unixes did.
Windows Server might be the purest descendent of the old Unix cathedral model, shipping integrated, Microsoft-developed software for all core functionality: kernel, userland, windowing system, webserver, compiler, etc. GNU also had such ambitions at one point, which explains some of their integration-oriented policies (some of which are disliked, and some of which have been dropped). For example, a unified style of command-line options (now packaged into getopt), a standard in-house-developed configuration/scripting/extension language that all applications were supposed to use (Guile), a unified compiler suite handling all languages (GCC), etc.
> But some components have gotten to be big enough that they're entire projects in themselves, usually cross-platform and not integrated with any one OS's development. Some of these are adopted into the BSD core respositories and customized so they form part of the integrated offering, but a number are just left in ports and run mostly unmodified.
I think this is pretty much what OP was trying to say, but his choice of words didn't make it obvious. The major difference between *BSD (OpenBSD is particularly picky about this) and Linux is that the "base" system is supposed to be fully-functional and well-integrated, from kernel to userspace, whereas Linux is "just" the kernel.
There are good uses to both models. I found the latter to be very useful in embedded systems, where you often need that kind of flexibility. I found the latter to be, frankly, a lot more useful on the desktop. To this day, I have to consult my notes every time I need to set up wireless on a Linux box without wicd or NetworkManager. The fact that a system with OpenBSD's reputation actually gets to do that easier is a good testimony to the merits of well-integrated userspace tools.
Sure. And that's always been the case. There's a question of what constitutes the "core OS", though in the case of the BSDs there's also a pretty strong tradition that this conforms largely to the state of BSD/UNIX in the late 1980s / early 1990s: kernel, libraries, userland, mail, DNS, lpd. While you can add a webserver to a UNIX system, it doesn't require one in the same way that, say, mail and cron are pretty much required to get basic tasks done.
I suspect Oracle's PoV is that a crappy 1970s proprietary database server and security-negative Java runtime are integral parts of every operating system and should be included by default, as well as the license compliance system required to manage them.
Windows Server is absolutely a Cathedral, though Microsoft has had its own reign over the system tempered by both legal and marketplace / partner considerations -- hands tied in the first case, business reality requiring they toss some scraps to their vassals in the second.
Drawing ideological boundaries is always a fraught process.
Traditional GNU/Linux systems include a great deal of BSD/MIT licensed software. Locally, I've got over 3100 packages installed on a Debian box. Running grep over /usr/share/doc/*/copyright I find:
2555 of these are GPL licensed, 774 BSD, 1462 reference MIT (this may include non-license references, "MIT License" nets 28 entries), 139 Apache, 25 Python, etc.
Stallman's argument is over the core of the OS, which he makes a fair case for being kernel + compiler + core libraries. In the case of Linux, that's straight up GNU for #'s 2 and 3.
The BSDs in general have fragmented rather less than GNU/Linux development has, though the latter have also captured a far larger deployment base, by most estimates. Adding Android to the mix, Linux competes with any end-user platform. BSD is also the root of many proprietary Unix variants, an intentional characteristic of its licensing model.
FreeBSD in general is aimed at the server and desktop niche with a particular expertise in networking. FreeBSD originated in the "UNIX Wars" of the early 1990s during which AT&T attempted to assert its trademark and copyright over the increasingly popular BSD and 386BSD ("1-800-ITS-UNIX") operating systems. That case was a landmark, with AT&T substantially failing to assert its claims. The ruling was largely sealed, but much of it was subsequently unsealed during the SCO v. IBM trial, greatly damaging SCO's case (also based on copyright claims over UNIX). Arguably the uncertainty generated by the lawsuit provided a toehold for Linux to gain in early critical popularity, though the openness of its development model also likely contributed to this.
NetBSD forked from FreeBSD with the aim of providing as broad a range of hardware support as possible, though arguably some GNU/Linux distros such as Debian have trumped it.
OpenBSD forked from NetBSD with the aim of providing a very high security platform. OpenBSD lags in many high-performance and scalability characteristics, but offers an exceptionally robust security profile and default deployment security characteristics. The project website has long bragged about its security record (presently "Only two remote holes in the default install, in a heck of a long time!"). Notable OpenBSD projects include the pf firewall suite and OpenSSH. There's also been a project to remove all GPL'd code from the OpenBSD release, though attempts by the original pf author to write a specific exclusion into his license for use in GPLd projects (which the BSD license otherwise allows) resulted in that codebase being removed and the suite rewritten from the ground up. Theo's ideological purity is different from Stallman's in bent, but no less strong in my opinion.
There are a few even smaller distros (notably DragonflyBSD), I'm less familiar with these.
Underlying all of the BSDs is the BSD license, which is "permissive", requiring only that the license text be included in derivative works -- those works themselves need not carry source distribution obligations as most of the GNU licenses (GPL, LGPL, GPLV2, GPLV3) do. The result (intentional) is that the BSDs are used in a wide range of proprietary products, not merely dedicated servers. I've found BSD in routers, load balancers, printers, fax machines, settops, and other devices, usually identifiable by nmap fingerprinting scans.