The MacOs(which stands for Macintosh Operating System)
was first introduced in 1984 with the orignal Machintosh the Macintosh 128K. It
is a completely graphical operating system with no command line interface
designed for workstation or home Desktops. MacOS has gone through two
significant design transitions since, and is undergoing a third. The first
transition was the shift from supporting only a single application at a time to
being able to cooperatively multitask multiple applications (MultiFinder); the
second was the shift from 68000 to PowerPC processors, which both preserved
backward binary compatibility with 68K applications and brought in an advanced
shared library management system for PowerPC(PPC) applications, replacing
the original 68K trap instruction-based code-sharing system. The third was the
merger of MacOS design ideas with a Unix-derived infrastructure in MacOS X.
MacOs supported file systems are supports HFS+, HFS, ISO 9660, FAT, UDF. It's
kernel is monolithic based on modules. Apple released Mac OS X Server 1.0 in
January, 1999. A public beta of Mac OS X was released in the year 2000, and
March 24, 2001, saw the full and official release of Mac OS X version 10.0.
Version 10.1 shipped on September 25, 2001, followed by the August 24, 2002,
release of Mac OS X 10.2 "Jaguar"; the October 24, 2003, release of Mac OS X
10.3 "Panther"; and the April 29, 2005, release of Mac OS X 10.4 "Tiger", Mac OS
X v10.5 "Leopard" (planned for release in late 2006) . These are based on a
modified version of Mac OS GUI, all versions known as Aqua.
The MacOS system of internal boundaries were very weak. There as an assumption
that there is but a single user, so there were no per-user privilege
groups. Multitasking was cooperative, not pre-emptive. All MultiFinder
applications run in the same address space, so bad code in any application can
corrupt anything outside the operating system's low-level kernel. Security
cracks against MacOS machines are very easy to write; the OS has been spared an
epidemic mainly because very few people are motivated to crack it. Because of
this, the company decided instead to acquire NeXT and use OPENSTEP as the basis
for their new OS . At first, the plan was to develop a new operating system
based almost entirely on an updated version of OpenStep, with an emulator —
known as the Blue Box — for running "classic" Macintosh applications. The result
was known under the code name Rhapsody, slated for release in late 1998.
The intended role for the Macintosh was as a client operating system for
nontechnical end users, implying a very low tolerance for interface complexity.
Developers in the Macintosh culture became very, very good at designing simple
interfaces.
Linux, first designed and distributed by Linus Torvalds, was originally developed for Intel 386 microprocessors and now supports all popular computer architectures including x86, Alpha, AMD64, PPC, SPARC etc. It is deployed in applications ranging from embedded systems (such as mobile phones and personal video recorders) to personal computers to supercomputers. Linus was inspired by Minix (a kernel and operating system developed by Andrew Tanenbaum), to develop a capable UNIX-like operating system that could be run on a PC, and now many other architectures. In the narrowest sense, the term Linux refers to the Linux kernel, but it is commonly used to describe entire Unix-like operating systems (also known as GNU/Linux) that are based on the Linux kernel combined with libraries and tools from the GNU project and other sources. Most broadly, a Linux distribution bundles large quantities of application software with the core system, and provides more user-friendly installation and upgrades. Linux does not include any code from the original Unix source tree, but it was designed from Unix standards to behave like a Unix.
Linux supports ext2, ext3, ReiserFS, FAT, ISO 9660, NFS file systems. It is based on (loadable) kernel modules into its monolithic kernel. It has very powerful security mechnisms and is virus and spyware free in contrast to other operating systems.
Windows NT (New Technology)3.1 was the first release of Windows NT, and came
out on July 27, 1993. The version number was chosen to match the one of Windows
3.1, then-latest OS from Microsoft. It could run on Intel x86, DEC Alpha, and
MIPS CPUs. Further release of windows NT 3.1 are NT 4.0, 2000, Windows XP
and Windows Server 2003.
NT has file attributes in some of its file system types. They are used in a
restricted way, to implement access-control lists on some file systems, and
don't affect development style very much. It also has a record-type distinction,
between text and binary files, that produces occasional annoyances (both NT and
OS/2 inherited this miss-feature from DOS). Latest released of Windows NT
supports NTFS, FAT, ISO 9660, UDF file systems. It is based on Hybrid kernels (microkernels
that have some "non-essential" code in kernel-space in order for that code to
run more quickly than it would were it to be in user-space). It supports both 32
and 62 bit architecture.