LibreOffice - Calc - LibreOffice Calc is the spreadsheet program you've always needed. A fork of OpenOffice.
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.
Microsoft Office Excel - Microsoft Office Excel is a commercial spreadsheet application.
Apache OpenOffice - Apache OpenOffice is an open source, office document productivity suite.
Microsoft 365 - Boost your productivity with reliable access anywhere with services like email, calendar, file sharing, meetings, instant messaging, and Office Online
Big Huge Labs Writer - Writer is a free online distraction free writing environment provided by Big Huge Labs.