You want to be careful though, even though its free it might not be in the future or it might not work when your children are running MSWindows 2025.
Keep your files in as open format as you can. Microsoft Word 2007 for example won't open a MS Word 2000 document unless you download the importer so if you used Word 2000 in the future your stuck. Stick with plain text or rich text or html, or something else that can be imported into most anything.