Open Source Software

Oss•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 Office.

•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 for them.

• Example:▫Linux▫Blender▫Codeblock▫Mozilla firefox▫Open office.org

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.

•Example:▫Adobe Flash▫Adobe Photoshop▫Windows office▫Windows xp

Difference b/w OSS and Proprietary S/wOSS Proprietary S/w

Purchased with its source code

Purchased without the source code

User can get Open source for free of charge

User must pay to get the proprietary software

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 computer

No one responsible for the software

Full support from vendor if anything happened to the software

Oss•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.

Oss• Apple Inc.[edit]• Apple II family

▫ Apple DOS▫ Apple Pascal▫ ProDOS▫ GS/OS

• Apple III▫ Apple SOS

• Apple Lisa▫ Lisa Workshop[1]

▫ Lisa Operating System[2]

• Apple Macintosh▫ Mac OS▫ A/UX (UNIX System V with BSD extensions)▫ Rhapsody▫ 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▫ iOS

•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 platforms.

Microsoft Corporation

•Xenix (licensed version of Unix; licensed to SCO in 1987)

•MSX-DOS (developed by MS Japan for the MSX 8-bit computer)

•MS-DOS (developed jointly with IBM, versions 1.0–6.22)

•Windows (16-bit and 32-bit preemptive and cooperative multitasking)▫Windows 1.0 (Windows 1)▫Windows 2.0 (Windows 2 - separate version for

i386 processor)▫Windows 3.0 (Windows 3)▫Windows 95 (Codename Chicago - Windows 4.0)▫Windows 98 (Codename Memphis - Windows

4.1)

Microsoft Corporation

▫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 Server 2003)▫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 Server 2012 (based on Windows 8)▫Windows 8 (Windows NT 6.2)▫Windows Phone 8▫Windows 8.1 (based on Windows 8)▫Windows Server 2012 R2 (based on Windows 8.1)

•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+

+ microkernel)•Unix (OS developed at Bell Labs ca 1970 initially

by Ken Thompson)•Xinu (Study OS developed by Douglas E. Comer in

the USA)

Non-proprietary

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▫ Android▫ bada▫ Firefox OS (project name: Boot to Gecko)▫ Openmoko Linux▫ OPhone▫ MeeGo (from merger of Maemo & Moblin)▫ Mobilinux▫ MotoMagx▫ Qt Extended▫ Sailfish OS▫ Tizen (earlier called LiMo Platform)▫ webOS

• PEN/GEOS, GEOS-SC, GEOS-SE• iOS (a subset of Mac OS X)• Palm OS• Symbian platform (successor to Symbian OS)• Windows Mobile (superseded by Windows Phone)

Advantages:•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 code.

•The implications of this are that bugs can be easily fixed.

•closed source if there is a bug in certain software the user must wait for a new release.

Contd.,•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 release.

•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]

Disadvantages•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 most up-to-date.

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 machine.

•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 multi-processor.

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 multi-processor machines.

•Unix differ from other OS in that it was developed in the high level C language rather than assembly language.

• It runs any architecture machine[the same applies to Linux]

Virtual Machine•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 physical interface.

•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 interface•OS done interface b/w applications and the

machine.•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.

•Example:• 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

same time.•To achieve this, the system must implement a

scheduling system.•Which connects each of the processes in turn to the

processor.• 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 parallel.

•The multi-tasking must be very sophisticated and not to user and process.

Memory management•The system has to control the physical memory of

the computer.• 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 processes.

• It also maintain zones of memory allocated to different processes which are helps to prevent the unauthorized modification.