Mozilla Thunderbird:
This email client is developed by Mozilla and allows for secure and customizable e-mailing.
-Compatible with Linux, Windows and Mac OS X

Firefox:
Firefox is a great browser, allows for "add-ons" which are user-developped applications. Firefox becomes the swiss army knife of browsers with these add-ons, as the amount of free, useful tools that are available is staggering.

Image Applications:
Gimp:
Is like Photoshop but free, with perhaps an interface that's not as nice.
However, it's powerful, and cross-platform.

Irfan view:
Is good to view your files.
Works on most Windows Operating Systems.

Paint dot NET:
This is a free image and photo editor for Windows.
Features:
-Unlimited undo
-Support for layers
-Special Effects
-Useful and diverse tools
-Compatible with Windows XP SP2 and later, Vista and Windows Server 2003

Xero plug-ins (for Photoshop):
Free plugins for Photoshop.
Windows only.


VSO Image Resizer:
Like the Windows XP Image Resizer, but for Vista (Microsoft has not yet released a Vista image resizer). It appears in the context menu for ease of use and has many options for resolution, quality, adding watermarks, and working on a batch of pictures at the same time. Easy to use. For Windows 2000, XP, Vista.

Multimedia Applications:
Audacity:
Free audio editor, cross-platform, very popular and very powerful.
Many features are available, including live recording, Import/Export, Editing, Effects, Plugins, etc.

CamStudio:
Camtasia-like software, can capture video of an area of your screen, or your whole desktop. Perfect for recording demonstrations, how-to videos, etc.
For 32 bit Windows. Can be downloaded directly at Sourceforge.

Winamp:
Free media player for Windows. Many custom skins are available. Features: customizable EQ, easy playlist editor, many free internet radio(shoutcast) and TV channels in the Media Library, etc.

Miro:
Plays internet TV and Radio, with available tutorial videos. Also, has options for HD. For Mac and Windows.

Exact Audio Copy:
CD ripper/encoder for Windows.
This page is a good guide for configuring and using Exact Audio Copy.

MP3 gain: This app can change all of your mp3s to the same volume, without altering the quality, so that you don't have adjust playback volume when you're listening to them. For Windows.

VLC:
Is cross platform, and will pretty much play any type of video. If you have many video, in many different encodings, VLC is your best bet. Has many features, depending on the OS it's installed on.

GOMPlayer:
Plays most popular audio/video codecs, and broken videos as well.

BurnAtOnce:
CD mastering/burning

DeepBurner Free:
DVD authoring/burning.

VideoHelp.com - Forum, Guides, Tools and hardware lists: A DVD authoring tool.
MediaMonkey:
Tag editing, music organizing application. Automatically connects with freedb, a huge music database, to add/edit tags.
Syncs with many portable media players, rips CDs in a variety of available formats, or burns audio or data CDs.
Converts audio from one format to another.
Automatic, logical organizing of your audio files. Also, playlist creation and equalizer.
For Windows.

TagScanner:
ID3 Tag editor, with ability to rename files based on tags, and edit tags based on filename/folder name. Access to freedb. Can edit playlists, and export them to HTML, Excel and CSV.

7zip:
Like a free WinRAR, for Windows.

Office Applications(word editors, etc):
Open Office:
This is an open-source office suite, and has different applications, including word, spreadsheet, presentation, graphics, database, and math editors.

PDF Creator:
It virtually prints any document into a PDF.
Compatible with any 32-bit Windows.

Foxit PDF Reader:
Faster than Adobe, free PDF reader.

Code Editors:
HTML-Kit:
Free HTML editor, as well as other language code-editing capabilities. Plug ins are available, and it can edit the files on the server directly, from a remote location, eliminating the need to download, edit, and upload the files.
For Windows.

First Page 2000 or 2006:
Version 2006 seems to have more features. Both are customizable HTML code editors. Features syntax highlighting, real time update to preview window (which can be viewed next to code window), custom tag creation, etc.

NVU:
A Dreamweaver/Frontpage style application allowing for faster development without knowledge of HTML code. Also supports some CSS. Available for Windows, Mac OS X and Linux.

Download Applications:
Phex:
P2P client that uses the GNUtella network. Works on Windows, Mac OS X, Linux, and other Operating Systems.

Filezilla:
A FTP client available for all platforms, and server available for Windows only.

AceTFP 3 Freeware:
A free FTP client for Windows.
Drag 'n drop UI. Connection preferences, ability to preview files, can resume broken transfers, and make direct server-to-server transfers.

Cyberduck:
FTP and SFTP (SSH Secure File Transfer) browser for Mac OS X.

Free Download Manager:
As it's name says, FDM is a free download tool that can speed up Downloads and has many cool features, including a dropbox in the bottom-right part of the screen, buttons in the right click menu that allows one to download one or all files on a page or directory, downloading bittorrent files and flash videos..etc.
For Windows.

Operating Systems::
Ubuntu:
A Linux distribution that comes with a full suite of applications, including an office suite. One can download a CD image and burn it, or request a free CD from the ubuntu website.

File/System Utilities, etc::

Recuva:
" 'freeware Windows utility to restore files that have been accidentally deleted from your computer' It is really nifty. Made by the same people that make CCleaner, it does what it says and looks simple to use."

JkDefrag:
JkDefrag is a disk defragmenter and optimizer for Windows 2000/2003/XP/Vista/2008/X64. Completely automatic and very easy to use, fast, low overhead, with several optimization strategies, and can handle floppies, USB disks, memory sticks, and anything else that looks like a disk to Windows. Included are a Windows version, a commandline version (for scheduling by the task scheduler or for use from administrator scripts), a screensaver version, a DLL library (for use from programming languages), versions for Windows X64, and the complete sources."


CCleaner:
freeware system optimization and privacy tool. It removes unused and temporary files from your system - allowing Windows to run faster, more efficiently and giving you more hard disk space. The best part is that it's fast! (normally taking less than a second to run) and Free." Really great for cleaning temporary files and finding registry issues.
For Windows
PC Inspector File Recovery:
Recovers files with FAT and NTFS file systems.
For Windows.

TweakUI:
"This PowerToy gives you access to system settings that are not exposed in the Windows XP default user interface, including mouse settings, Explorer settings, taskbar settings, and more."
For Windows XP.

Virtual Desktop Manager:
"Manage up to four desktops from the Windows taskbar with this PowerToy."
For Windows XP.

Synergy:
Allows one to work on several computers with one same mouse and keyboard. Works with different OSes at the same time, and one can easily switch from one to the next. Click the link for more details.

Miscellaneous::
HydraIRC:
IRC client for windows.

ClearType Tuner:
"This PowerToy lets you use ClearType technology to make it easier to read text on your screen, and installs in the Control Panel for easy access."
For Windows XP

System Security::
Ad-Aware:
Spyware protection at its best. For Windows.

Spybot Search and Destroy:
Detects spyware, removes it. For Windows.

AVG Free edition:
This is a powerful antivirus, its virus database is frequently updated, with no headaches for the user. For Windows.

ZoneAlarm Free edition:
"ZoneAlarm is an easy-to-use firewall that blocks hackers and other unknown threats." You can control what your computer connects to, and weed out what's bad and unwanted. Once you've got it configured, it gives peace of mind; also has "game mode", where you won't be bothered by prompts from ZoneAlarm interrupting your game. For Windows

Great freeware/"gratis" software sites!
Ramsinks: All of the programs featured on this site have apparently been tested to be spy-ware and ad-ware free. Some is trialware, but apparently those have functionality.

SnapFiles - software reviews, download freeware and free trial programs:
A website that provides a good search engine and nice descriptions for free applications, and trialware.

Requests:
-Screen Capture applications (Camtasia style programs)
-Movie editing
-Gif creator
-Free OS distributions (i.e Linux distributions)
-Compilers
-Dreamweaver-style programs
-Macromedia Flash style programs