BS”D in Mac OS X and iOS Internals

There is no correlation between the number of processes and the “clarity” of an operating system. You are comparing apples and gooseberries.

On a Linux system, ps ax will show a lot of processes that consume no memory and have a name in square brackets, like this:

root         2  0.0  0.0      0     0 ?        S    Nov02   0:01 [kthreadd]
root         3  0.0  0.0      0     0 ?        S    Nov02   4:39 [ksoftirqd/0]
root         6  0.0  0.0      0     0 ?        S    Nov02   0:00 [migration/0]
root         7  0.0  0.0      0     0 ?        S    Nov02   0:01 [watchdog/0]
root         8  0.0  0.0      0     0 ?        S    Nov02   0:00 [migration/1]

These processes are part of the kernel. They run with kernel privileges, but they are managed like user processes by the scheduler (many of them with high priority because they handle hardware requests). The machine I'm writing this on has over 100 such processes — how many you have will depend on many things, including your kernel version, your hardware and what kernel services you run (e.g. some filesystems have kernel daemons).

These processes probably account for a large part of the different numbers. As far as I know, none of the BSD report such tasks separately, which makes your comparison meaningless.

In addition, a default OpenBSD installation includes very few services, whereas a default Ubuntu installation runs everything the average user expects to find. If you install the same software on both machines, you'll find similar numbers of non-kernel processes.

PC-BSD is FreeBSD with many enhancements to make a convenient, comfortable desktop environment, their "Push Button Installer" package management tool, a network utility and a unified control panel for easy access to admin utilities. So, yes, FreeBSD can be made to work like PC-BSD—that's exactly what the PC-BSD team have done!

If you want a graphical desktop system to get you started learning *BSD, then I would think PC-BSD is the ideal place to start—it gets you up and running with one of several popular desktop environments from the get-go, so you can then focus on learning other aspects of the system. If, on the other hand, you want to get your hands dirty from the beginning, learning how to install FreeBSD and additional software, you can use the ports system to add the extras you want.

As for the documentation, the vast majority of documentation relevant to FreeBSD will also apply to PC-BSD without modification, so the PC-BSD team focus their efforts on documenting the differences.

You can install PBI packages on a FreeBSD system—simply install the ports-mgmt/pbi-manager port, which provides the command line utilities for managing PBI packages. There is also sysutils/easypbi, which aims to provide a simple interface for creating PBI modules from FreeBSD ports. There are also ports of the PC-BSD network utility, their warden jail utility and others.