Open Office by Sun Microsystems. This is free software available from http://www.openoffice.org. Like Microsoft Office, it contains programs for word processing (called Writer), spreadsheets (called Calc), and presentations (called Impress).
iWork by Apple. This is a fee-based product, and contains programs for word processing (called Pages), spreadsheets (called Numbers), and presentations (called Keynote).
Works by Microsoft. This is a fee-based product that usually comes installed on new PC if you do not order Microsoft Office. It contains a word processor and a spreadsheet program.
Word Perfect by Corel. This is a fee-based product. It contains word processing, spreadsheet, and presentation programs.
