Spell checker
From Freeplane - free mind mapping and knowledge management software
Spell checker how-to
To enable spell checking, select one of the supported languages using pop-up menu→languages→[your language]. from any editor.
The option to "Disable Spellchecker" works like a choice of language, corresponding to "none".
Some spell checker options can be configured from Preferences->Behavior->Spell checker options.
You can install another dictionaries copying them into <freeplane-install>/resources/ortho. The dictionary files dictionary_XX.ortho converted from aspell are available on http://sourceforge.net/projects/freeplane/files/spell_check_dictionaries/ .