Open Source Software is software which is free and is also freely modifiable, meaning users are free to modify the program to their own specifications.
Open Office - An office suite (similar to Microsoft Office or Corel Office Suite). Includes Word Processor, Spreadsheet, Presentation (Slide Show) Maker, Database, and Drawing Application.
The GIMP - Professional image editing and drawing program.
Celestia - 3D astronomy software.
Audacity - Sound editing/recording software
Ardour - Digital Audio Workstation for recording, non-destructive editing, multitrack mixer.
Edubuntu - Version of the Ubuntu Linux Operating System including a number of popular open source educational software. (note: linux is an operating system that can be used instead of Microsoft Windows or Mac OS. If you are unsure of what linux is, it is recommended you research it further before attempting to install this software on a machine already conataining an Operating System.
Compiz Fusion - Youtube video of what can be done with Compiz Fusion on Linux. Compiz Fuzion is a windows manager for linux. Compiz Fusion is now included in Edubuntu (and other ubuntu flavours). See above link.
Ubuntu: Christian Edition - Ubuntu with various Christian themes and programs such as GnomeSword, Bible Memorizer, e-Sword, and web content filtering (parental control). Note: The current version of Ubuntu:CE is one version behind the main Ubunutu editions (Ubuntu, Edubuntu, Xubuntu, Kubuntu). It is recommended you install one of these main versions instead, and then install the Christian software separately.
Pidgin - Messenger/Chat software which includes protocols for MSN Messenger, Yahoo Messenger, IRC, and many others.
Filezilla - FTP Program for transfering files between your computer and a website/file server.
Firefox - An open source webbrowser that works better than Internet Explorer
Free Software is free to be used for certain purposes, but it is not open source, and therefore you are not allowed to modify the code.
Foxit PDF Reader - PDF Reader that is much smaller and quicker than Adobe PDF Reader
MrExcel.com - Sign up for a digital copy of MrExel's digital book. Very good book that teaches one how to use Excel. Includes numerous pictures and examples.