Basket - A note taking application for KDE. Lots of features.
Xmind - Xmind is a brainstorming and mind mapping application.
Parabol - Agile Meeting Co-Pilot
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
tl;dv - 📆 Add tl;dv to any meeting from any provider 🎥 Capture meeting moments on the fly --> Save everyone's time --> Keep colleagues up to date
FeatureMap - FeatureMap story mapping, simple and effective realtime collaboration and collective intelligence tool.