Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI. It allows to draw all UML2 diagrams and specific diagrams for business process modeling. It is easy and powerful with the capacity to add new functionalities to the application.
Gaphor is a WYSIWYG (What You See Is What You Get) UML and SysML modeling environment easy to use that will help you create your applications.
Gaphor Features
UML Designer provides a set of common diagrams to work with UML 2.5 models. The intent is to provide an easy way to make the transition from UML to domain specific modeling.
UML Designer Features
Cradle by 3SL is a requirements management and software / systems engineering tool for agile and phase-based projects including MBSE, agile development, document & project management. Cradle supports small or large teams, either co-located or distributed.
Cradle Features
Open source tool that provides methodological guidance, intuitive model editing, and viewing capabilities for Systems, Software and Hardware Architects.
Eclipse Capella Features