Software makes a computer useful and is the reason you use a computer. It allows you to type documents, surf the web, listen to music, play games and hundreds of other tasks. Everybody knows about "normal" (commercial proprietary) software. You buy it at a store and pay an exorbitant price for a plastic disk, some paper and a cardboard box. You go home and insert the plastic disk into your computer and start the installation. After you've inattentively clicked through the installation, you are prompted to accept a cryptic license. You carelessly scan through the seemingly unimportant jumble of legal nonsense, but unknown to you, usually include restrictions and limitations like:

1. You can only install the software on 1 computer, else you have to buy another license.
2. Only 1 user may use the software at any 1 time.
3. Files created with the program can only be used or transfered to 5 or less computers.
4. You can not copy any part of the software.
5. You can not give/sell the software to anyone.
6. You can not examine how the software works.
7. You can not alter the software in any way.
8. The company can collect information about your computer at any time.
9. The software can install and or disable your other software for any reason.
10. If your computer gets corrupted because of the software it's your fault.
11. You give up all rights not listed in the license.

Then you regrettably, or more likely, mindlessly "accept" the license by clicking the "I Accept" button. Then you're in for more "excitement" because many programs then have you enter a product activation key like: 4hBIt-3JFVu-8rMgj-87c96-7RO98. You painstakingly enter the key character by character, but to no avail; somewhere there's an error. Besides being nearly impossible to enter, it actually doesn't hinder a knowledgeable computer cracker* from installing the software without accepting the license or even buying it. There's almost always a loophole or an exploitable weakness. So, the only person it's hindering is you -- the respectable person. But finally, you enter the correct key and finish the installation.

Now, there just has to be some other software out there without all the restrictions and encumbering rubbish. What would be nice is if there was free software that you could freely, share and if you're so inclined, modify to your liking. Well there is, and it's called Open-Source Software.

Open-Source software is a totally different philosophy of software development. With open-source licensed software you are given more rights and freedoms in using the software. For instance, with proprietary software (non-open-source, ie. you buy it) all the above licensing restrictions can apply. So, if the license says: "For use on only 1 computer", and you want to install the software on your other computer you can't legally. You would have to go the store and buy another copy, or call the company and buy another license of the software. But in contrast, open-source software has written in its license the freedom to redistribute (share) as much as you want.

But, your rights and freedoms don't stop at just free redistribution. There are several other rights to the software that you receive; unlike proprietary software, where you only receive restrictions. The Open-Source Initiative (OSI), the organization responsible for approving open-source licenses, lists the rights that every open-source software must give the user:

1. Free Redistribution: the software can be freely given away or sold.
2. Source Code: the source code* must either be included or freely obtainable.
3. Derived Works: redistribution of modifications must be allowed.
4. Integrity of The Author's Source Code: any modifications must state that they are not from the original author to protect him.
5. No Discrimination Against Persons, Groups or Fields of Endeavors: no one can be locked out or excluded.
6. Distribution of License: The rights attached to the program must apply to all whom the program is redistributed without the need for execution of an additional license by those parties.
7. License Must Not Be Specific to a Product: the program cannot be licensed only as part of a larger distribution.
8. License Must Not Restrict Other Software: the license cannot insist that any other software it is distributed with must also be open-source.
9. License Must Be Technology-Neutral: no click-wrap licenses or other medium-specific ways of accepting the license must be required.

These rights and freedoms give the user great value to the developers, and allow for a superior development environment. The software is now able to quickly benefit more users, and henceforth speed up and improve development. There are many examples of the widespread use of high quality open-source software. Just to list a few examples:

• MySQL, the world's most popular open-source database, has a market share of over 30%. Putting it at between the third or second most used database in existence.
• Over 60.64% of the entire Internet uses the open-source web server Apache.
• Over 75.8% of the top 500 supercomputers use open-source operating systems (75.2% use Linux, and 0.6% use BSD based).
• Almost all dynamic webpages use an open-source scripting language like: PHP, Perl or Python.
• Nearly all of the Internet is controlled by open-source software. This includes: BIND (DNS server), Sendmail (email server), Majordomo (email list manager), etc.

But, open-source software is not just for the corporate server environment. There is countless quality free software for home users. Anything from free alternatives for: Internet Explorer, Outlook, Microsoft Office, iTunes, Photoshop, Dreamweaver, and even more. There are even open-source games.

But, where do you get all this software? You don't have to waste your time going out to a store, or pay exorbitant prices from online retailers. No, it's all as easy as downloading the software for free from the Internet. And there are even sites that have a searchable database of open-source software, so you don't have to rummage through the entire Internet looking for quality open-source software.

For more information see the Open-Source FAQ

There are many sites that have detailed lists of available open-source software. But, on this site I list the top 2-6 open-source software for major types of software. All the listed software is popular and of high quality. The list is divided into major categories:

• Home Users - Includes: common end-user programs like web browser, office suit, media player, etc.,
• Power User - Includes: development, server and system software
• Games - Includes: First-Person Shooters, Real-Time Strategy, etc., (list not complete)

On each of the pages is the list organized by type of software. For each type there will be 2-6 programs sorted by features/quality/popularity. The one at the top is "theoretically" the "best", and each subsequent one is less capable. Although, almost all of the time each program is just as powerful as the others, and user preference is the only deciding factor. Below is an example of the list.

You can find more lists at: Wikipedia, Freshmeat, SourceForge, Free Software Directory, SourceWell, IceWalkers, OpenDEN, OSDir, OSSwin.

There are many sites and books that detailedly discuss open-source software. Below is just a few to get you started.

• Wikipedia: Open-Source, Open-Source Movement, Open-Source Software, Open-Source Definition, Open-Source License, GNU General Public License
• Wikibooks: Open-Source
• Books: The Cathedral and the Bazaar, Open Sources: Voices from the Open Source Revolution, Free as in Freedom: Richard Stallman's Crusade for Free Software
• Articles: The Great Software Debate: Technology and Ideology, Realizing the Promise of Open Source in the Nonprofit Sector, Why Open Source Software? Look at the Numbers!, Understanding Open Source Software, Anarchism Triumpant: Free Software and the Death of Copyright
• PDFs: Coarse's Penguin, or, Linux and The Nature of the Firm, A Software Engineering aproach to Libre Software, The Contestation of Code, UK Parliament report on Open Source