There is a growing collection of free, well written software out there and this is a list of some of the applications I use.

Many of them can be run standalone so are perfect for carrying around on a USB stick. Take a look at PortableApps.com for free portable versions.

Firefox
The open-source, free, standards compliant web browser. Have a look at my Recommended Firefox Plugins for some useful addons.

OpenOffice
OpenOffice.org 3 is an open-source office software suite for word processing, spreadsheets, presentations, graphics, databases and more. It stores all your data in an international open standard format and can also read and write files from other common office software packages. It can be downloaded and used completely free of charge for any purpose.

Notepad++
Notepad++ is a free text and source code editor and Notepad replacement that supports several languages.

MP3Tag
MP3Tag is a powerful and yet beautifully simple tool to edit metadata of common audio formats where it supports ID3v1, ID3v2.3, ID3v2.4, iTunes MP4, WMA, Vorbis Comments and APE Tags.

Treesize Free
Treesize Free shows you how the space has been used within a collection of directories.

FileZilla
An FTP manager including both client and server components.

The Gimp
The free, open source image manipulation program with capabilities similar to Photoshop and Paintshop Pro.

Inkscape
An Open Source vector graphics editor, with capabilities similar to Illustrator, CorelDraw, or Xara X, using the W3C standard Scalable Vector Graphics (SVG) file format.

CDBurnerXP
CDBurnerXP is a free application to burn CDs and DVDs, including Blu-Ray and HD-DVDs. It also includes the feature to burn and create ISOs, as well as a multilanguage interface. Everyone, even companies, can use it for free.

7-Zip
7-Zip is a file archiver with a high compression ratio that can handle 7z,zip,gz and rar archives. Why bother with WinZip or WinRar?