Fully functional following of HTML links stored in the nodes, be it www links or links to local files.
From very early versions, Freemind supports folding which is its essential property.
Fast one-click navigation, including folding / unfolding on one click and following links on one click at the same time (you don't have to make choice between fast following of links and fast fold/unfold). You can move the map by dragging the map's background as well as using mouse wheel.
Undo
Smart Drag'n Drop, including the possibility to copy nodes or copy style of nodes; dragging and dropping of multiple selected nodes; dropping of texts or list of files from outside
Smart copying and pasting into, including pasting of links from HTML or structuring the pasted content on the basis of the number of leading spaces in a line; pasting of lists of selected files
Smart copying and pasting from, including plain text and RTF (MS Wordpad, MS Word, MS Outlook messages).
Export of map to HTML, with folding (see example (http://freemind.sourceforge.net/PublicMaps-exported.html))
Find facility, where found items are shown one by one as you do "find next", and the map is unfolded only for the current item.
Possibility to use and edit long multiline nodes; even with newlines
Possibility to decorate nodes with built-in icons, colors and different fonts.
Low costs of risk of switching away to another mind mapping tool, because FreeMind stores maps in XML format. If you have a lot of maps created by FreeMind and you want to switch to another program, writing a conversion program should be easy, especially if that program features Visual Basic scripting facility. Christoph Rissner describes in his article (http://krottmaier.cgv.tugraz.at/docs/seminar/sem2002_mindmaps.pdf) at IICM site (http://krottmaier.cgv.tugraz.at/veranstaltungen/seminar/abgeschlossen.html) his implementation (http://krottmaier.cgv.tugraz.at/docs/seminar/sem2002_mindmaps.tar.gz) of data exchange between FreeMind and MindManager.
File mode enables you to browse the files on your computer, seeing the folder structure as mind map.
See more details in Freemind development tree (http://freemind.sourceforge.net/Freemind-development.html)