7-Zip
7-Zip is a free file archive manager that supports many different formats, including ZIP and RAR.

Amarok
Amarok is a music player for Linux with an intuitive interface, and many impressive features.

Audacity
Audacity is a free sound editing and recording application.

Blender
Blender is a 3D modeling and animation program.

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

Dia
Dia is a diagram and graph drawing application, originally based on Microsoft Visio, that makes it easy to draw flow charts, graphs and other diagrams.

Digsby
A three-in-one application that includes an Instant Messenger client, email notifications, and social network integration with sites like twitter and facebook.

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.

Mendeley
Mendeley helps you to manage a collection of research papers, and supports automatic extraction of metadata from PDFs.

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

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.

Pidgin
Pidgin, formerly known as Gaim, is a multi-protocol instant messenger client, working with Yahoo IM, AIM, Google talk, MSN and others.

SciTE
A feature packed text editor with many advances features for programmers.

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.

Synergy
Synergy lets you easily share a single mouse and keyboard between multiple computers with different operating systems.

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.

Wireshark
Wireshark is a network protocol analyzer with many advanced features.