Adium
A great Instant Messaging application for OSX that supports many different IM networks and protocols.

Audacity
Audacity is a free sound editing and recording application.

Blender
Blender is a 3D modeling and animation program.

Cyberduck
Extremely simple to use open source FTP and SFTP client for the Mac, which seamlessly integrates with a number of other Mac applications.

Deluge
A lightweight cross-platform BitTorrent application that has plugin support.

FileZilla
FileZilla is a cross-platform FTP client that supports secure file transfer.

Firefox
Firefox is an excellent free browser that provides a much more secure and friendly browsing experience that Microsoft Internet Explorer.

GIMP
GIMP (The GNU Image Manipulation Program) is a free image editor similar to Photoshop. It can be used for things like photo retouching, image composition and image authoring.

Google Earth
Google Earth combines satellite imagery, maps, terrain and buildings onto a 3D globe that you can move around.

Handbrake
Handbrake is a DVD ripping application, allowing you to convert a DVD to a video file.

Inkscape
Inkscape is an open-source vector graphics editor similar to Adobe Illustrator or Corel Draw.

Miro
A video player with access to over 1000 Internet TV channels.

NeoOffice
NeoOffice is a native Mac OSX port of OpenOffice.

NVu
A complete Web Authoring System that rivals programs such as FrontPage and Dreamweaver.

OpenOffice
OpenOffice is a free and full featured alternative to Microsoft's office suite.

Opera
An award winning free Web browser that is a very fast and feature packed.

Scribus
Scribus is a Desktop Publishing (DTP) application which can be used to create professional quality documents.

Skype
Skype allows you to make phone calls from your computer - to other skype users for free, and very cheaply to phones and mobiles.

Thunderbird
Simple and lightweight email and news application.

Transmission
A very lightweight and easy to use BitTorrent application.

VLC media player
VLC is a media player that supports many different audio and video file formats.