Design  

Blender.
3D graphic modeling, animation, rendering and playback.

Dia.
Flexible diagram drawing.

GNU Image Manipulation Program.
Retouch digital photos and create graphics.

Inkscape.
Vector graphics editor.

Nvu.
Create web pages with no knowledge of HTML.
Replace DreamWeaver and Frontpage.

Scribus.
Advanced Desktop publishing.

Tuxpaint.
Drawing program for children ages 3 to 12.

Games 

Battle for Wesnoth.
Turn-based strategy game with a fantasy theme.

Enigma.
Uncover pairs of identically colored Oxyd stones while solving puzzles.

Neverball.
Miniature golf and an obstacle course.

Sokoban YASC.
Put all of the crates into the designated areas by nudging them.

Internet 

Azureus.
Client for distributing large files via the BitTorrent protocol.

FileZilla.
A fast and reliable FTP client and server.
Replace CuteFTP!

Mozilla Firefox.
A secure and fast web browser.
Replace Internet Explorer!

Pidgin.
A multi-protocol instant messaging (IM) client.

HTTrack.
Download websites for offline viewing.

RSSOwl.
Keep up with your favourite internet news feeds on your desktop.

SeaMonkey.
An all-in-one web browser, e-mail, newsgroup, IRC client and HTML editer.

Mozilla Thunderbird.
A full-featured email client - Reclaim your inbox!
Replace Outlook Express!

TightVNC.
See the desktop of a remote computer and control it.

WinSCP.
SFTP and SCP client.

Multimedia 

Audacity.
Record, edit and mix audio.

Celestia.
Explore the universe in three dimensions.

Really Slick Screensavers.
Mindbending OpenGL screensavers.

Stellarium.
Planetarium on your PC.

Sumatra PDF.
A lightweight PDF reader.

VLC.
Video and audio player.

Productivity 

GnuCash.
Personal and business accountancy.
Replace Quicken and MS-Money!

MoinMoin Desktop Edition.
A wiki that runs on your computer.

Notepad2.
A fast text editor with some advanced features.

OpenOffice.org2.
Comprehensive office software.
Replace MS Office Suite!

PDF Creator.
Generate PDF documents from any program.
Replace Adobe Acrobat!

Utilities

7-Zip.
Compress and uncompress files in a wide variety of formats.
Replace PKzip and WinZip!

Abakt.
Schedule and execute backups of your data.

ClamWin.
Antivirus software with automatic updating.
Totally Free Antivirus!

GIMP Tool Kit (GTK+).
Multi-platform toolkit for creating graphical user interfaces.
Replace PhotoShop!

TrueCrypt.
Encrypt and secure your valuable data.

Workrave.
Prevent and recover from Repetitive Strain Injury (RSI).

OpenDisc (Formerly OpenCD)

Established in 2007, the OpenDisc project provides a collection of high quality Open Source Software for Windows on a disc, and is updated at regular intervals throughout the year. There are tens of thousands of OSS programs available for free download, making it difficult to separate the quality and truly useful offerings from those in need of further development. The landscape is made even more complicated by the availability of a vast number of Shareware and Freeware programs that you can also download freely from the net. These, however are not Open Source, because the author does not share the human readable source code for others to examine and build upon.

Open Source Software

Open Source Software (OSS) is provided with a license that gives the end user the right to use it freely for private or commercial use. You also have the right to inspect and even modify the underlying source code. You can give away or sell the original version you received or one with your modification, though you may be required to in turn pass on the modified source code so that others can benefit from the changes you have made. This last clause protects the developer's work from unfair exploitation by others, while allowing the source code to be released to the community. You are not required to pay royalties to previous developers, but you are still permitted to charge money for the sale of OSS.

If you have no interest in source code, you may ask why OSS even matters. One answer is that the release of source allows external observers to inspect the internal functions of the program, which means you can be confident that the program treats your private data with respect.

One problem with proprietary software is that it tends to use closed file formats to store your data. Once the parent company stops supporting older versions of a proprietary program, you may therefore have to upgrade to newer versions of that program, at significant expense, in order to retain access to your data. This does not happen with OSS, because when the source code for opening and saving files is available, a third party can easily write an import filter for the next generation of software, ensuring that your data will always be available.

Finally, the release of source code has in some cases spawned large communities of volunteer developers who have in turn provided the world with highly useful, and entirely free software such as Linux, OpenOffice.org, and Mozilla. These are then available free of charge to schools or anyone else who may not have a large budget available for software. So, you can see that the freedom of software is important for everyone, not just software developers.x