An excelent office suite that fullfills all needs in office work.Include all major components from SpreadSheets to Wordprocessing,Database and Presentation.

Uses OpenDocument standard for document exchange with other software, and yes it can work with .doc | .xls | .ppt files.

use Writer for wordprocessing with on-the-fly pdf creation

use Calc for spreadcheats calculations

use Impress for slideshow presentention 

use Base for database work/edit/interface

use Math for special mathematical works

use Draw for vector design

A very complete suite.test it! 

WebSite:http://www.openoffice.org/