Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)
TiddlyMap - An interactive concept- and mind-mapping plugin for the personal note-taking software TiddlyWiki based on the Vis.js library. It's free and open-source!
Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.
Wisdomap - Wisdomap Medicine is a study aid that helps medical students create differential diagnoses and suitable management plans from a presenting complaint and structured revision notes.
UML Designer - UML Designer provides a set of common diagrams to work with UML 2.5 models.
IOctopus - IOctopus is an online mind map service for a dive deep into the mind for the best ideas.