Freeware

Windows
Any Video Converter: convert video files from one format to another
Audacity: audio file editor
AVG anti-virus free edition: anti-virus software
Avira anti-virus free edition: anti-virus software
CamStudio: record what you see on your screen
CCleaner: removes non-essential files
Chrome: Google's web browser
dscaler: view television on your PC
FileZilla FTP Client: File Transfer Protocol client
Fileseek: File search tool
Firefox: web browser
Foxit Reader: a fully featured PDF reader
FreeUndelete: recover deleted files
The GIMP: a fully featured image editor
IrfanView: an image viewer with batch editing features
LibreOffice: free office sweet, including word processor, spreadsheet and presentation software
Malwarebytes Anti-Malware: remove malware
mp3gain: balance the volume levels of a selection of mp3 files
MusicBrainz Picard: rename and set tag information on audio files
Paint.net: image manipulation tool
PC Inspector's File Recovery: resurrect deleted or lost files
Safari: Windows version of Apple's web browser
Spyware Terminator: protect against spyware
Startup Control Panel: manage programs that run at startup
TreeSize: graphical representation of hard-drive usage
Tweak UI: Microsoft Power Toy offering many customisation options for Windows XP
VideoLAN VLC media player: multimedia player
Virtual Dub: video editing and conversion software
Winamp: mp3 player
WinHTTrack Website Copier: Save a copy of an entire website to your hard-drive
XChat: Internet relay chat client

Linux
Epiphany: web browser for GNOME desktop environment
Evince: pdf viewer
The GIMP: a fully featured image editor
Guayadeque: Music player
Konqueror: file and web browser for K desktop environment
Midori: lightweight web browser
Pan: Usenet newsgroup client
XChat: Internet Relay Chat client
XFCE: lightweight desktop environment