Dr.Explain - Dr.Explain software is a help file authoring tool.
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.
Document360 - Self-service knowledge base software focused on SaaS Products & Enterprise Software Projects.
Microsoft 365 - Boost your productivity with reliable access anywhere with services like email, calendar, file sharing, meetings, instant messaging, and Office Online
WinCHM - Creating CHM file, Make CHM file, Web Help. WinCHM Pro - Help authoring software (CHM, WebHelp, DOC, PDF) . With this powerful tool you can not only create chm file from scratch, but also convert a set of existing HTML files to a chm file.
ONLYOFFICE - ONLYOFFICE is a complete office and productivity suite.