How to read pdf and OpenDocument
PDF (Portable Document Format) and OpenDocument are recognised international standards for documents. Both formats are "open" : they are freely available to anyone to implement, so you aren't forced to go to one vendor to get the software to read them.
To find a PDF reader visit http://en.wikipedia.org/wiki/List_of_PDF_software
OpenDocument is typically used in office suites (word processors, spreadsheets, drawing applications, etc.)To find software to read or edit OpenDocument files: http://www.opendocumentfellowship.org/applications