Freeplane began as a fork of the Freemind project. While maintaining comparability with Freemind file format, it has far outpaced in features and development. As of 3/5/2022, the latest Freeplane update (1.9.3) is 3/5/2022 vs Freemind was last updated (1.0.1) 2/5/2016. Active, helpful community.
Google Docs - Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.
Xmind - Xmind is a brainstorming and mind mapping application.
Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.
FreeMind - FreeMind is a premier free mind-mapping software written in Java.
Wondershare PDFelement - All-in-one PDF editor
vym - VYM (View Your Mind) is a tool to generate and manipulate maps which show your thoughts.