LibreOffice - Free office suite, open source, and compatible with .doc, .docx, .xls, .xlsx, .ppt, .pptx files. Updated regularly – download for free. Originally based on OpenOffice.org.
Siag Office - Siag Office is a free to use office suite designed for the UNIX based operating systems.
SoftMaker Office - SoftMaker Office is one of the most powerful and reliable office suite that is fully compatible with the MS Office Suite.
Microsoft Office 365 - Microsoft Office is an office suite of desktop applications, servers, and services for the Microsoft Windows and OS X operating systems.
Microsoft 365 - Boost your productivity with reliable access anywhere with services like email, calendar, file sharing, meetings, instant messaging, and Office Online
Calligra Office - Calligra Office that is also called as Calligra Suite is the pack of multiple applications and tools that are being offered by the MS Office Suite.