LibreOffice is a private, free and open source office suite – the successor project to OpenOffice.
It’s compatible with Microsoft Office/365 files (.doc, .docx, .xls, .xlsx, .ppt, .pptx) and is backed by a non-profit organization.

Try out FreeOffice, and you will then undoubtedly agree that it is the best free alternative to Microsoft Office.

FreeOffice is a complete Office suite with a word processor, a spreadsheet application and a presentation program – all seamlessly compatible with their counterparts in Microsoft Office (Word, Excel and PowerPoint).