MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
Playscii - Full-featured ASCII art and graphic editor and game creation tool
Visio - Simplify and communicate complex information using data-linked diagrams.
draw.io - Online diagramming application
IOctopus - IOctopus is an online mind map service for a dive deep into the mind for the best ideas.
UMLGraph - UMLGraph is a professional automated drawing tool that allows the designers the declarative specification and drawing of UML class and sequence diagram.