iText - iText is an intuitive and refined text editor with word processing completely rewritten in Cocoa...
Microsoft Office Excel - Microsoft Office Excel is a commercial spreadsheet application.
PSPDFKit - PSPDFKit is the best framework for working with PDF files. Our SDK provides first-rate PDF solutions for your application with features like annotating, signing, and form filling. We power successful projects for businesses across the globe.
Google Sheets - Synchronizing, online-based word processor, part of Google Drive.
UniDoc.io - PDF & Office Libraries In Pure Golang.
LibreOffice - Calc - LibreOffice Calc is the spreadsheet program you've always needed. A fork of OpenOffice.