What used to be Mozilla Aplication Suite is now SeaMonkey. New name, new project and also - new team. Its a a fine heir to Mozilla, all things considered. The packet includes all the tools for working on the net, browser, html redactor, email and news clients, address books and irc. Add ons and plug ins can personalize each fresh install and the browse is fast and fairly stable - decent choice for surfing the web. Do I even have to mention its open source?
You may download the Windows version here.
The linux version is here.
Aaand the MacOS?