overview of foss

8/3/2019 Overview of FOSS

1/39


2/39

Standards in Real Life -

Nuts and Bolts

Generally speaking, nuts

and bolts come in standard

sizes. If you loose a nut, you can

run to the hardware store

and buy another one of the

same size.


3/39


Pipes and Fittings

Plumbing pipe comes in standard

sizes and fittings

You can choose your plumber based on quality of service, not

on the brand of pipe you have.


4/39


Electrical Plugs (andvoltage!)

Think about how many

electronic devices exist

today in your home. This would not be possible

without standardization of

electrical power delivery.


5/39


Connections

Almost all external

computing devices are now

USB Eliminates questions such

as do you need a serial or

PS/2 mouse?


6/39


Moreplugs

Audio

Video


7/39


HowWeb Sites Work

GET /index.html HTTP/1.1

Host:www.example.com

HTTP/1.1 200 OK

Date: Mon, 23 May 2005 22:38:34 GMT

Server: Apache/1.3.27 (Unix) (Red-Hat/Linux)

Last-Modified: Wed, 08 Jan 2003 23:11:55 GMT

Etag: "3f80f-1b6-3e1cb03b"

Accept-Ranges: bytes

Content-Length: 438

Connection: close

Content-Type: text/html; charset=UTF-8


8/39

Whatis a Standard?

A set of criteria (some of which may be mandatory), voluntary

guidelines, and best practices.


9/39

Who Creates Standards?

Strictly speaking, an official standard is only produced by an officiallyrecognized standards organization, such as ISO, ANSI, NEMA, NIST,

IASB, ITU, ...

IETF, IEEE, W3C, OASIS, Blu-ray Disc Association (BDA) etc. are

industry consortia, where groups of companies and individuals get

together to produce an industry standard. Industry consortia mayproduce eitheropen or closed standards.

Entities (people, companies, or software projects) may publish a

specification that is open and free to use. This is called an open

standard.

Companies may license a specification and charge royalties for its use.

This is called a closed standard.


10/39

What makes a standard Open?

Available Anyone is allowed to read and implement the standard.

No Royalties Free to implement without paying hefty licensing fees orroyalties.

Not controlled by a single vendor - Maximizes end-user choiceand makes the market more competitive with no lock-in to a single vendor's

implementation.


11/39

The Internet Runs on Standard Protocols

Something called TCP

/IP

came along and became thestandard network protocol.

Why? Because it was completely free and open for anyone

to implement.


12/39

Technology Standards thatwork

SMTP (email)

Completely open protocol

Allows you to communicate with someone else on the Internet

just by knowing their email address.


13/39

Where are the Standards?

Web BrowserWars

W3C an organization that defines web standards, the

authority on what constitutes valid HTML.

Major Web Browsers during the late 1990's:- Microsoft Internet Explorer (IE)

- Netscape Navigator


14/39

Open Document Format (ODF)

Completely open standard, anyone can read the

specifications and use this format.

Accepted as an ISO standard.


15/39

DefiningTerms

Proprietary Software

Open Source Software


16/39

Proprietary Software

Source code availability

Source code not provided

Source code provided - may or may not includepermission to create modifications and enhancements

Restrictions on dissemination

Warranties provided

Maintenance and support terms included


17/39


Open Source software generally is distributed under a license

that guarantees the right to read, modify, redistribute and use

the software freely. No indemnification;

No maintenance or support.


18/39


19/39


Mozilla Firefoxwebbrowser

http://www.mozilla.com

Browser is safer than Internet

Explorer

Reduce chances of gettingbadware on your computer

Adheres to web standards

(HTML, CSS)

This is the recommended web

browser at FLMNH.


20/39


OpenOffice Productivity Suite

http://www.openoffice.org

Supports Open Document

Format (ODF).

Output to PDF. Completely Free!


21/39

Freeware

Freeware is free software, software that the licensee can use

without paying a license fee.

Free software may be proprietary software for which sourcecode is not provided (Adobe Acrobat) or open source software

(Linux).

Note:

Not all open source software is free; not allproprietary software is licensed for a fee.


22/39

Open Source Software License - Licensees

Original software owner or developer chooses to limit

the rights that he asserts over licensees

Licensees, subject to license terms, can: make and distribute copies of software;

build upon software to create modifications or other

works.


23/39

Open Source Software Licenses - Source Code

Source code to original product always provided; Licensee can modify or enhance source code

Licensee may be prohibited from charging royalties


24/39

Open Source Software License Warranties

and Support

Generally, software provided AS-IS with no

warranties, warranties excluded;

No indemnification;

No maintenance or support.


25/39

PopularFree software licenses

GNU General Public License

GNU LesserGeneral Public License

BSD License Mozilla Public License

MIT License

Apache License


26/39

The GNU General PublicLicense (GPL)

No standard open source license, but GPL most widely used(roughly 85% of open source software);

Terms include: User freedom to distribute and/or modify; Requirement that original and modified source code be always

made available to the world under the terms of the original license; Must retain copyright notices and warranty disclaimers; Does not include grant of patent licenses;

Extremely viral license.


27/39

Advantages: Proprietary Software

Indemnification;

Maintenance and support;


28/39

Disadvantages: Proprietary Software

COST! License fee Product bundlingexample: Microsoft office.

Licensee cannot modify or enhance the code; Often not built to open standards, leading to interoperability

problems; Shut off from continuing development and information sharing

in open source community; Some proprietary code is not as good as its open source

counterparts.


29/39

Advantages: Open Source License

PRICE: Generally no or low license fees; Availability of source code coupled with permission to

make modifications; Access open source development community, which

may be very active with respect to code used.Continuing improvement; outstanding development;

More likely to be built to open standards, so

interoperable with other open standards systems.


30/39

Disadvantages: Open Source Licensing

No indemnification; if a third party claims that licensee isusing code that the third party developed, the licenseehas no one to pay his legal fees and damage award

(SCO v. IBM); No maintenance and support (unless purchased

separately); No warranties regarding media, viruses, and

performance; Staff must be open source savvy; License terms are NOT standard: thus important to pay

close attention to terms.


31/39

Open Standards and International Cooperation

Open standards are essential for us to develop our own

standards and applications. Proprietary products force us

into long-term contracts and provide no flexibility for us to

develop according to our needs.


32/39

ADVANTAGESOF FREE SOFTWARE

freedom to run the program for any purpose.

freedom to study and modify the program.

freedom to copy the program so you can help your neighbor. freedom to improve the program, and release your

improvements to the public, so that the whole community

benefits


33/39

Why Use Shells?

Well, most likely because the are a simple way to string together a bunch

of UNIX commands for execution at any time without the need for prior

compilation. Also because its generally fast to get a script going.

Shell History

The basic shells come in three main language forms.These are (in order of creation) sh, csh and ksh


34/39

The shell

The shell acts as an interface between the user and thekernel.

When a user logs in, the login program checks the usernameand password, and then starts another program called theshell. The shell is a command line interpreter (CLI). Itinterprets the commands the user types in and arranges forthem to be carried out. The commands are themselves

programs: when they terminate, the shell gives the user another prompt (% on our systems).


35/39

Bourne Shell

Historically the sh language was the first to be created and

goes under the name of The Bourne Shell. It has a very

compact syntax which makes it obtuse for novice users butvery efficient when used by experts. It also contains some

powerful constructs built in.


36/39

C Shell

Next up was The C Shell (csh), so called because of the

similar syntactical structures to the C language. The UNIX

man pages contain almost twice as much information for theC Shell as the pages for the Bourne shell, leading most users

to believe that it is twice as good.


37/39

Korne Shell

The Korne shell can be thought of as a superset of the

Bourne shell as it contains the whole of the Bourne shell world

within its own syntax rules. The extensions over and abovethe Bourne shell exceed even the level of functionality

available within the C Shell (but without any of the

compromises!), making it the obvious language of choice for

real scripters.


38/39

The kernel

The kernel of UNIX is the hub of the operating system: it

allocates time and memory to programs and handles the filestore and communications in response to system calls.

As an illustration of the way that the shell and the kernel worktogether, suppose a user types rm myfile (which has theeffect of removing the file myfile). The shell searches the file

store for the file containing the program rm, and then requeststhe kernel, through system calls, to execute the program rmon myfile. When the process rm myfile has finished running,the shell then returns the UNIX prompt % to the user,indicating that it is waiting for further commands.


39/39

The Directory StructureAll the files are grouped together in the directory structure. The file-

system is arranged in a hierarchical structure, like an inverted tree. Thetop of the hierarchy is traditionally called root (written as a slash / )

overview of foss

Documents