Most flavors of Linux are free including, but not limited to:
Distribution
(I believe all these distributions are free)
Debian based
Knoppix
The first Live CD (later DVD) version of Debian GNU/Linux. There are several versions of Knoppix
Linux Mint Debian Edition
Available in both 32 and 64-bit as a live DVD with a Gnome desktop. The purpose of LMDE is to look identical to the main Linux Mint edition and to provide the same functionality while using Debian as a base
MEPIS
Includes lightweight variant called antiX. antiX is meant to be used on older computers with limited hardware.
MintPPC
For PowerPC computers.
Parsix
Optimized for personal computers.
PureOS
Based on Debian Testing.
Symphony OS
Current version includes the Mezzo desktop environment. Previous versions were based on Knoppix.
Ubuntu
Aims to offer a complete and polished desktop on a single CD. There are several versions of Ubuntu
Gentoo based
Sabayon Linux
An installable Live DVD with multiple desktop environments. Sabayon uses the rolling release model; it uses a customized version of Red Hat's Anaconda Installer and includes a Media Center application.
RPM based
Fedora
Community supported distribution sponsored by Red Hat.
SUSE Linux
A desktop-oriented Linux distribution by Novell, Inc.
Turbolinux
Based on Red Hat Linux.
Currently most distributions include a graphical user environment, with the two most popular environments being GNOME (which can utilize additional shells such as the default GNOME Shell, the Ubuntu Unity), and the KDE Plasma Desktop. Others include Unity, Xfce, and LDXE. Some Linux kernel versions will run on hardware designed for Macintosh. Some versions will also run on PDAs, notebooks, gaming consols, etc.
See the attached link for more information.
There are also free versions of Unix: FreeBSD, NetBSD and OpenBSD. See the attached links for locations to download.
Some operating systems that are available with new laptop computers are some more common systems like the following: Windows Vista, and the Vista Ultimate.
There are many types of single user operating systems available today; they encompass the systems found on mobile phones and personal computers. Examples of popular single user, multitasking operating systems, for example, include Windows, Linux, and Mac OS X.
DOS meaning Disc Operating System
Microsoft Windows, Mac OS X, and Linux
Free operating systems based on Linux (e.g. Ubuntu) Unix based operating systems (e.g. Apple's) Proprietary operating systems that are locked into one manufacturer and therefore expensive (e.g. MS Windows).
Ubuntu Linux.
Certainly not. There are hundreds of operating systems designed for countless kinds of computers. Even within the personal computer market, there have been and are still many choices available for operating systems, such as Windows, Mac OS X, Linux, and FreeBSD. Traditional or less mainstream operating systems for personal computers, such as MS-DOS, FreeDOS, AmigaOS, and BeOS are also available.
Some operating systems that are available with new laptop computers are some more common systems like the following: Windows Vista, and the Vista Ultimate.
NOTHING!
There are many types of single user operating systems available today; they encompass the systems found on mobile phones and personal computers. Examples of popular single user, multitasking operating systems, for example, include Windows, Linux, and Mac OS X.
DOS meaning Disc Operating System
Microsoft Windows, Mac OS X, and Linux
Microsoft makes the most popular operating systems, eg:Windows XPWindows VistaWindows 7They are propriety operating systems (made by a company and sold). You can also get open source operating systems which are free, eg:Linux Ubuntu
IBM's pg. 366 operating systems
Free operating systems based on Linux (e.g. Ubuntu) Unix based operating systems (e.g. Apple's) Proprietary operating systems that are locked into one manufacturer and therefore expensive (e.g. MS Windows).
There are a number of free operating systems for personal computers. They include Linux, NetBSD, GNU, Open Solaris, Darwin, Free DOS, AROS, eCOS and Haiku.
Windows was the first operating system and only operating system for many years. Therefore people know what to expect from it. Before Microsoft, there were many computers and operating systems. Computers systems were either mainframes including IBM OS, minicomputers, midrange computers, and graphical workstations. They had commercial level operating systems that were used to run businesses, laboratories, schools, etc. All cost tens or hundreds of thousand of dollars or more. None were suitably priced for home use or for office desktop use. Personal Computers running Microsoft Windows were the first consumer level systems marketed to and available for personal and home use for a few thousand dollars. Being first, they cornered the market and established a name and reputation. There were no competitors at that price range and Microsoft was aggressive in preventing copycats.