EduDo - EduDo is a video discussion platform
Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.
Courseroot - Biggest online course database on the web
Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)
TeenUp - A learning platform designed for teens by teens
UML Designer - UML Designer provides a set of common diagrams to work with UML 2.5 models.