Many commercial office packages have open source, or at least free, alternatives available. Many of these products are also available across platforms. Many conform to a published, open standard.
Rather than Mi¢ro$oft Office, try OpenOffice with:
try as rather than OOo Writer word processor M$ Word OOo Draw drawings M$ Visio
OOo Calc spreadsheet M$ Excel OOo Impress M$ PowerPoint OOo Base database M$ Access
These are able to read and write Mi¢ro$oft documents, and write PDFs.
Many extensions are available.
OpenOffice does not contain a true replacement for Publisher or Visio.
Rather than Mi¢ro$oft Publisher, try Scribus.
Unfortunately, this can not read or write Publisher documents.
Rather than Mi¢ro$oft Outlook, try
These are not as extensive as Outlook in functionality, but may be better for home use.
Drawing and Artwork
Rather the Adobe Photo$hop, try the GIMP.
Mathematics and CAS
The computer algebra system Mathematica from Wolfram Research is very expensive.
For alternatives, see my post on CAS software.
I’d recommend Cobian Backup.
There are many other free and open-source source control tools out there, including some very interesing ones. I like Subversion partly because it is relatively light-weight, configurable (yet with very sensible defaults), easy to install, and has active development and support communities.
To create PDF files from any application, try PDFCreator.
Real Player is horrible adware and Windoze Media Player is pretty horrible too; try instead Real Alternative, which includes Media Player Classic.