Office Pack for Document, Spreadsheet and Slide is the best free office software - perfect altenative Microsoft Office (Word, Excel & PowerPoint).
It's fully compatible with Microsoft Office (Word, Excel, PowerPoint & Txt), Google Docs, Google Sheets, Google Slides and OpenOffice format for Windows.
Plenty of formats supported, such as:(.docx, .docm, .dotx, .dotm); (.doc and .dot); (.wpd); (.odt, .ott, .oth, .odm, .sxw, .stw, and .sxg) (.xls, .xlw, and .xlt); (.xlsx, .xlsm, .xltx, .xltm); (.xlsb); (.xml); (.ods, .ots, .sxc and .stc) And much more!