According to their website, Mozilla says:

SeaMonkey® is the all-in-one application formerly known as the "Mozilla Application Suite", containing a web browser, a mail and newsgroups client, an HTML editor, web development tools, and an IRC chat client.

Probably the SeaMonkey browser is not as full featured as FireFox 3.0.9(current), because SeaMonkey is trying to be a "Jack-of-all-Trades".

Application packages support commonly performed business functions and usually is two or more bundled programs for the computer that help to address specific needs of the business. Accounting packages and illustration packages are different types of application packages.

The Mozilla Sunbird application can be downloaded from many different websites and platforms. The most reliable websites to download from are Mozilla and cNet.

Mozilla firefox is an internet application for searching and browsing the internet. You have to download it first using a different browser.

The Firefox project began as an experimental branch of the Mozilla project by Dave Hyatt, Joe Hewitt and Blake Ross. They believed the commercial requirements of Netscape's sponsorship and developer-driven feature creep compromised the utility of the Mozilla browser To combat what they experienced as the Mozilla Suite's software bloat, they created a stand-alone browser, with which they intended to replace the Mozilla Suite. On April 3, 2003, the Mozilla Organization announced that they contrived to change their focus from the Mozilla Suite to Firefox and Thunderbird .