6 completely free multi platform software that you may not have known was out there.

1: Battle for Wesnoth
One of the best games out there. The Battle for Wesnoth is a turn-based strategy game with a fantasy theme.

Build up a great army, gradually turning raw recruits into hardened veterans. In later games, recall your toughest warriors and form a deadly host against whom none can stand! Choose units from a large pool of specialists, and hand-pick a force with the right strengths to fight well on different terrains against all manner of opposition.

200+ unit types. 16 races. 6 major factions. The world of Wesnoth is absolutely huge and limited only by your creativity - make your own custom units, compose your own maps, and write your own scenarios or even full-blown campaigns. You can also challenge up to 8 friends - or strangers - and fight in epic multi-player fantasy battles.

2: OpenOffice.org
With Base, Calc, Draw, Math, Impress, and Writer under it's belt there is really no reason to use Microsoft Office. OpenOffice.org the product is a multi-platform office productivity suite. It includes the key desktop applications, such as a word processor, spreadsheet, presentation manager, and drawing program, with a user interface and feature set similar to other office suites. Sophisticated and flexible, OpenOffice.org also works transparently with a variety of file formats, including those of Microsoft Office.

3: Opera Best Browser Ever! Opera is a cross-platform web browser and Internet suite which handles common Internet-related tasks including visiting web sites, sending and receiving e-mail messages, managing contacts, chatting online, viewing Widgets, downloading BitTorrents, and reading Newsfeeds. Opera's lightweight mobile web browser Opera Mini and most current versions of its desktop application are offered free of charge.

4: Audacity Only thing I use to make ringtones :-). Audacity is a digital audio editor application. Audacity is cross-platform, using the wxWidgets software library to provide a similar graphical user interface on several different operating systems.

5: Pidgin Pidgin (formerly named Gaim) is a multi-platform instant messaging client that supports many commonly used instant messaging protocols.

6: AbiWord When you just need a simple word processor.