Open Source ...

The basic concept of open source software is that the source code is available to the party consuming the software and he/she is free to modify the source.

There can be lots of variations on the above thing and hence a number of licences are available to cover all situations - software being free or not is a separate issue and is definitely not necessary but most open source softwares are also free. An important concept is that of copyleft. Basically if you give out your source for free and someone else starts making money off it by modifying the source and distributing only the binaries, the basic purpose of open source is defeated. So Richard Stallman came up with this technique (more on him below) and created a licence called the GNU Public Licence. This licence is viral, if you change the source of a GPL software and want to distribute it further it has to be distributed under GPL

Here is another good definition.

The free software movement was popularised by Richard Stallman (known as RSM). He got frustrated by closed source software and restrictions that did not allow him to hack them. He then made it his mission to create a system of only open source components. He wrote the popular emacs editor and the gcc compiler himself and released it open source. Visit this site for more info.

Another person known by the three letter acronym of ESR - Eric S Raymond - is a source of a lot of insight into the open source movement. His major work is Cathedral and the Bazaar. This essay prompted Netscape into releasing their browser as open source. He was also embroiled in the famous Halloween Papers.

Yipee!! Wiki

A Wiki is really good tool for collaborative working. Its basically a collection of webpages that can be edited by anyone. I think Wikis became popular with open source projects because it took the concept of freedom to another level. If anybody could modify the source of the actual thing why not the documentation. Its one more way of trusting your fellow beings to do the right thing. Centralized control, approval process etc really belong to the feudal age. The actual proof of the pudding is that it actually works and is more efficient. If I find a broken link on a wiki, I just fix it rather than curse the author and move on. Even if I were to take the pains of sending a mail to the author and then he would fix it, its so much more inefficient.

The Mozilla site takes this concept a step further. Their main site itself is editable (unlike most other projects who keep a read-only website and a separate wiki). Just go to this page and scroll to the bottom - you will see a edit this page link.

Another website which really illustrates the success story that wiki is - wikipedia. This online encyclopedia has now become my reference of choice. Its free, fair and huge. It just completed three years of existence and has already surpassed encyclopedia Britannica. The articles in wikipedia really seem fair, uptodate, correct and unbiased. With anybody having edit rights people would probably not let incorrect stuff remain there for long. Here is some info that you will find new - the name Mozilla wasn't derived from Godzilla :-) Go here and add wikipedia to your list of search engines in firefox (and get firefox if you haven't already).

BTW wikipedia has a cousin called wikiquote too.