OpenOffice - This application suite is similar to Microsoft Office and is recommended for students and/or parents as an alternative if they are unable obtain Microsoft Office.
OpenOffice can be downloaded from http://www.openoffice.org.
LibreOffice - This application suite is similar to Microsoft Office and can also be recommended if students/parents are unable to obtain Microsoft Office. The difference between OpenOffice and LibreOffice are minimal and comes down to personal preference as most of the features are accessed the same and the user interfaces are very similar between the two suites.
LibreOffice can be downloaded at http://www.libreoffice.org.