different kinds of free
| freeware |
free software |
| software available for free but not modifiable, e.g. Picasa, iTunes, Internet Explorer |
software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction |
Unless you are a programmer, this is largely a philosophical distinction.
pros and cons of free
| pros |
cons |
| free! |
documentation and support sometimes lacking |
| flexible (e.g. Open Office can open and save multiple file formats) |
programs work a little differently from the ones you may be used to |
free software
| Open Office |
a full suite of programs to replace Microsoft Office |
| the GIMP (Gnu Image Manipulation Program) |
an alternative to Adobe Photoshop |
| Firefox |
a powerful and highly customizable web browser |
| VLC media player |
supports multiple formats of streaming video |
| Stellarium |
a fun application for tracking the night sky |
| much, much more |
a huge list of open source software from Wikipedia, including everything from assistive technology to chat clients to games |
free operating systems
Here's a PDF handout with all this information.