Firefox:

Firefox 2 delivers helpful new features to make your online experience more productive.
Firefox continues to lead the way in online security, and now includes active protection from online scams to keep you safer. Choose from over a thousand useful add-ons that enhance Firefox. It’s easy to personalize Firefox to make it your own.

Thunderbird:

Full-Featured Email
Simple to use, powerful, and customizable, Thunderbird is a full-featured email application. Thunderbird supports IMAP and POP mail protocols, as well as HTML mail formatting. Easily import your existing email accounts and messages. Built-in RSS capabilities, powerful quick search, spell check as you type, global inbox, deleting attachments and advanced message filtering round out Thunderbird’s modern feature set.
Junk Mail Filters
Each email you receive passes through Thunderbird’s leading-edge junk mail filters. Each time you mark messages as spam, Thunderbird improves its filtering so you can spend more time reading the mail that matters. Thunderbird will also use your mail provider’s spam filters to keep junk mail out of your inbox.
Anti-Phishing Protection
Thunderbird protects you from increasingly common email scams—also known as “phishing”—which try to fool you into handing over your passwords and other personal information. Thunderbird will tell you when it thinks a message might be a scam.
Advanced Security
Thunderbird provides enterprise and government grade security features including S/MIME, digital signing, message encryption, support for certificates and security devices. Attachments are never run without your express permission, protecting you from many worms and viruses.
Automatic Updates
The new Software Update feature makes it easy to get the latest security and feature updates to Thunderbird. Thunderbird automatically downloads these small updates in the background and prompts you when they are ready to be installed.
Customize Thunderbird
Select new button controls for your toolbars, install extensions to add new features, or change the look of your browser with themes—the way Thunderbird looks and works is under your control.

WordPress is a state-of-the-art semantic personal publishing platform with a focus on aesthetics, web standards, and usability. What a mouthful. WordPress is both free and priceless at the same time.

More simply, WordPress is what you use when you want to work with your blogging software, not fight it.

Mambo is a full-featured content management system that can be used for everything from simple websites to complex corporate applications. Continue reading for a detailed feature list.

*A large and healthy user and developer community.

*Provides a basic level of content approval for registered users.

*Online help.

*Page caching mechanism to improve performance on busy sites.

*Trash manager

*Advertising management (banners, etc).

*Media (images, documents) upload and management.

*Content display scheduling.

*Content syndication (RSS).

*Search engine friendly (SEF) URL’s.

*Internationalisation (interface translation).

*Content macro language (aka mambots).

*Advanced and separate system administation system.

*Advanced package/addon/template deployment system.

*Simple but powerful template system (written mostly in HTML, no complex templating syntax to learn, just a couple of PHP functions to include).

*Heirarchial user access groups.

*Basic visitor statistics.

*Multiple WYSIWYG content editor support

*Simple polls

*Content voting/rating system.null

osCommerce is an Open Source based online shop e-commerce solution that is available for free under the GNU General Public License. It features a rich set of out-of-the-box online shopping cart functionality that allows store owners to setup, run, and maintain their online stores with minimum effort and with no costs, fees, or limitations involved.

osCommerce has attracted the largest community for an e-commerce solution that consists of over 127,700 store owners and developers worldwide with add-ons being contributed on a daily basis. To date there are over 3,800 add-ons available that have been created by the community to extend the features of an osCommerce online store.

Group-Office is a Groupware suite containing a base system and different modules. The modules are designed in a way that groups of people can collaborate online. Shared calendars, addressbooks, projects, files and e-mail are the key features of the project. Users use their favorite browser to access their groupware from all over the world. Combined with the powerful Linux operating system it is a complete enterprise solution for the small to medium enterprise.