@workaholic Thank you for your question. @phaedryx‘s link http://en.wikipedia.org/wiki/List_of_collaborative_software goes a long way to showing what “open source” software is. Put simply, it is free software that anyone may use and also anyone may develop and change to create variations and special cases without having to pay a royalty to anyone. “Closed source” is the opposite of this.
You may have heard of Linux. Linux is another computer operating system (open source) that competes for users against Microsoft Windows (closed source) and Apple Macintosh (closed source). Anyone can take the operating source code for Linux and modify it to their own peculiar needs, whereas nobody is allowed to do that with Microsoft’s Windows or Apple’s Macintosh operating systems, under the pain of very expensive court cases.
To try and understand the term “source code”, right click anywhere on this page and select “view page source”. It will look like gobbledygook, but that is what is written for a computer to give us this web page. Here’s a part view from the top (after the asterisks):
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<!DOCTYPE html PUBLIC ”-//W3C//DTD XHTML 1.0 Strict//EN”
“http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd”>
<html xmlns=“http://www.w3.org/1999/xhtml” xmlns:fb=“http://www.facebook.com/2008/fbml” xml:lang=“en”>
<head>
<script type=“text/javascript”>var _sf_startpt=(new Date()).getTime()</script>
<title>What is the best collaborative software?</title>
<meta name=“description” content=“There’s Cube, Central Desktop, etc…
I work for a small organization that needs collab software mainly for shared projects (MS word docs, spreadshe”/>
<meta http-equiv=“Content-Type” content=“text/html; charset=utf-8” />
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This is only a small part of this page’s code. If you were to copy and paste everything from the source page that this sample is taken from and place it into an html editor, at the end of the process you would have replicated this page.
This is just a very brief introduction to source code, but I hope I have answered your question.
A similar thing happens with programmes like email clients (Outlook Express, for example) and every other thing that can be done in and with computers.