Classnotes | UNIX01 | RecentChanges | Preferences As was mentioned before, Linux is really just an operating system kernel sitting underneath a large number of utilities (most of which are GNU utilities). The kernel itself has grown in astounding ways since it's creation, and some of the more useful modern features include:
True-multitasking : From day-one it has been a true-multitasking system.
True-multiuser : Multiple users running programs and connected at the same time.
Processor agnostic: Not quite, but it does run on a large number of diverse processors. It can also be a true 64-bit OS.
Memory protection across processes: So that one process can't bring the whole system down.
SMP support: Linux has excellent support of SMP systems including NUMA support.
Partial POSIX compliance as well as System V and BSD features: Basically, it combines the best of all worlds.
Advanced, Journalling Filesystems: Linux actually has about half-a-dozen to choose from.
Performance optimizations: These are available as a patch for the current 2.4 series, but will be included in 2.6 when it is finally released.
Scalabale: It can run on everything from a PDA to a Mainframe. Many people use it as a server. Others use it as a desktop. It's also used in clusters all the time. (My DVD player is powered by Linux).
Stable: It has many fault-tolerant features that help keep Linux systems up and running.
Distributions
Linux and all the utilities for Linux are available as source code which can be downloaded and compiled for your use. However, that can be difficult and time consuming. Thus, there are distributions of Linux which do all these things for you and provide you a single, often simple, installation package for getting Linux onto your hardware.
Debian is a non-commercial, community-driven distribution which can be tricky to install, but is one of the easiest to maintain. It is currently my favorite distribution, and if you stick around to UNIX02 and UNIX03, you will learn all about it.
Gentoo is a relatively new distro, and one which has gathered a lot of attention. It was recently voted the most popular Linux distro in use at Novell, and is presently the distro with the fastest growing user base. The real draw for Gentoo is that you can use it to make a highly optimized Linux installation.
There are many others, and you can find out all about them here:
