Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
Document360 - Self-service knowledge base software focused on SaaS Products & Enterprise Software Projects.
Standard Notes - A safe place for your notes, thoughts, and life's work
ProProfs Knowledge Base - ProProfs Knowledge Base is a cutting-edge knowledge management software that assists businesses to reduces support tickets by self-help and create online manuals, guides, wikis, documentation, FAQs and more.
Joplin - Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.
GitBook - Modern Publishing, Simply taking your books from ideas to finished, polished books.