• Open source means that the basic coding is available
for others to add to or change to their requirements or
help in the development of the software, such as Open
• OSS is a software that is free to use and which provides
the original source code used to create it so that
advanced users can modify it to make it work better
Proprietary Software( closed source)
• Proprietary software is copyright and the code is
not available for changes or modification by
anyone but the developer.
• Company that developed the software and owns
the software and no one may duplicate it (or)
distribute it without that company’s permission.
• User have to pay to the software company they
want to use the software.
Difference b/w OSS and Proprietary S/w
Purchased with its source
Purchased without the source
User can get Open source for
free of charge
User must pay to get the
User can modify the software
User cannot modify
Users can install software
freely into any computer
User must have licence from
the vendor before install into
No one responsible for the
Full support from vendor if
anything happened to the
• Blender; 3D modeling software written in Python
and C++ that can make animations and games
• SimPy; queue-theoretic event-based simulator
written in Python
• flightgear is an open source flight simulator
written for Windows, Mac OS X, and GNU/Linux.
list of operating systems
• Computer Operating systems can be categorized by
technology, ownership, licensing, working state,
usage, and by many other characteristics.
• Apple Inc.
• Apple II family
▫ Apple DOS
▫ Apple Pascal
• Apple III
▫ Apple SOS
• Apple Lisa
▫ Lisa Workshop
▫ Lisa Operating System
• Apple Macintosh
▫ Mac OS
▫ A/UX (UNIX System V with BSD extensions)
▫ OS X (formerly Mac OS X)
▫ OS X Server (formerly Mac OS X Server)
• Apple Network Server
▫ IBM AIX (Apple-customized)
• Apple Newton
▫ Newton OS
• iPhone, iPod Touch, iPad
• Google Chrome OS is designed to work exclusively
with web applications. Announced on July 7, 2009,
Chrome OS is currently publicly available and was
released summer 2011. The Chrome OS source
code was released on November 19, 2009 under
the BSD license as Chromium OS.
• Chromium OS is an open source operating system
development version of Google Chrome OS. Both
operating systems are based on the Linux kernel.
• Android is an operating system for mobile devices.
Android is based on Linux core.
• es is a computer operating system developed
originally by Nintendo and since 2008 by Google.
It is open source and runs natively on x86
• Xenix (licensed version of Unix; licensed to SCO in
• MSX-DOS (developed by MS Japan for the MSX 8-bit
• MS-DOS (developed jointly with IBM, versions 1.0–
• Windows (16-bit and 32-bit preemptive and
▫ Windows 1.0 (Windows 1)
▫ Windows 2.0 (Windows 2 - separate version for
▫ Windows 3.0 (Windows 3)
▫ Windows 95 (Codename Chicago - Windows 4.0)
▫ Windows 98 (Codename Memphis - Windows
▫ Windows Millennium Edition (Windows Me Windows 4.9)
• Windows NT (Full 32-bit or 64-bit kernel, not
dependent on MS-DOS)
▫ Windows 2000 (Windows NT 5.0)
▫ Windows XP (Windows NT 5.1)
▫ Windows Server 2003 (Windows NT 5.2)
▫ Windows Vista (Windows NT 6.0)
▫ Windows Azure (Cloud OS Platform) 2009
▫ Windows Home Server (based on Windows
▫ Windows Server 2008 (based on Windows Vista)
▫ Windows 7 (Windows NT 6.1)
▫ Windows Server 2008 R2 (based on Windows 7)
▫ Windows Home Server 2011 (based on Windows
Server 2008 R2)
• Windows CE (OS for handhelds,
embedded devices, and real-time
applications that is similar to other
versions of Windows)
▫ Windows CE 3.0
▫ Windows CE 5.0
▫ Windows CE 6.0
▫ Windows Mobile (based on Windows
CE, but for a smaller form factor)
▫ Windows Phone 7
▫ Windows Phone 8
• Minix (study OS developed by
Andrew S. Tanenbaum in the Netherlands)
• Plan 9 (distributed OS developed at Bell Labs,
based on original Unix design principles yet
functionally different and going much further)
▫ Inferno (distributed OS derived from Plan 9,
originally from Bell Labs)
▫ Plan B (distributed OS derived from Plan 9 and Off+
• Unix (OS developed at Bell Labs ca 1970 initially
by Ken Thompson)
• Xinu (Study OS developed by Douglas E. Comer in
Disk Operating Systems
• 86-DOS (developed at Seattle Computer Products
by Tim Paterson for the new Intel 808x CPUs;
licensed to Microsoft, became PC DOS/MS-DOS.
Also known by its working title QDOS.)
▫ PC DOS (IBM's DOS variant, developed jointly with
Microsoft, versions 1.0–7.0, 2000, 7.10)
▫ MS-DOS (Microsoft's DOS variant for OEM,
developed jointly with IBM, versions 1.x–6.22
Microsoft's now abandoned DOS variant)
Smartphones and Mobile phones
• BlackBerry OS
• Embedded Linux
Access Linux Platform
Firefox OS (project name: Boot to Gecko)
MeeGo (from merger of Maemo & Moblin)
Tizen (earlier called LiMo Platform)
PEN/GEOS, GEOS-SC, GEOS-SE
iOS (a subset of Mac OS X)
Symbian platform (successor to Symbian OS)
Windows Mobile (superseded by Windows Phone)
• Possibly the biggest advantage of open source
software is the fact that everybody has the right to
modify and tweak the source code. This means the
code can be implemented in other pieces of
software and adapted to changing environments.
• any number of people, skilled or otherwise, have
now become programmers of the open source
• The implications of this are that bugs can be easily
• closed source if there is a bug in certain software
the user must wait for a new release.
• The re-distribution of open source code is also
promoted. Meaning that a bug fix can be instantly
re-distributed instead of having to wait for a newer
• no profit to be made, new versions are being
released all the time.
• large number of sources for support.
• completely free in every sense of the word.[It is
free to use, free to distribute, and free to modify]
• Closed source software companies pay salaries to
people to develop the software and therefore
development is pretty much guaranteed.
• so many developments are going on at the same
time it is hard to keep track of which version is the
Types of Operating System
• Single Task Systems : only one task may be run in
the system at a time, and therefore only one person
may work at a time. However, the process may
make use of the whole resource and power of the
• Multi-task systems: several processes can be
executed in parallel. Operating time is cut up into
small duration intervals and each process is
executed during these short periods.[prioritization
and scheduling algorithm].
• These systems may be multi-user as well as multiprocessor.
In Unix[Role of OS]
• The first Unix version only supported single
processor PCs, which may support multi-tasking
and multi-user systems.
• Today, information technology has advanced and
therefore Unix systems are capable to also exploit
• Unix differ from other OS in that it was developed in
the high level C language rather than assembly
• It runs any architecture machine[the same applies
• The OS gives the user and program he uses, what
amounts to a virtual machine within the real one.
• The virtual machine operates on the physical
machine which contains low level programming
interface, and provides high-level abstractions as
well as advanced programming and interface.
• 1950-programmers needed to be familier with the
• Modern system- provide higher level interface.
• The OS encapsulate physical layer and its diversity.
[frees developers form complexity of managing all
the existing peripherals]
• OS done interface b/w applications and the
• For this reason, All the internal and external
processes are delegated(Assign) to the OS.
• If the system available on several machine
architecture, the users and programming interfaces
will be the same on all of them.
• If the developer wants to read the contents of a file,
he carries out the same operation whether the file is
on tape, CD-Rom,Pendrive,HDD etc..
• The kernel of the OS carries out different operation
according to the peripherals the file is contained in.
Sharing the processor
• Multi-tasking – several programs(processes) at the
• To achieve this, the system must implement a
• Which connects each of the processes in turn to the
• If no cycling with single processor then it can run
only one process at a time.
• The OS cycling the processes rapidly, machine users
impress that the system execute the program in
• The multi-tasking must be very sophisticated and
not to user and process.
• The system has to control the physical memory of
• In multi-tasking the OS must implement very
strict(exact) control of memory.
• Because, the available physical memory is
insufficient, the system uses part of the disk as
auxiliary memory(swap area).
• The OS must be capable of efficiently controlling
memory in order to meet the demands of different
• It also maintain zones of memory allocated to
different processes which are helps to prevent the