Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.

Diagrammix - Tool for efficiently building attractive diagrams.

Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)

yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.

ARIS Express - ARIS Express is based on the proven ARIS methodology and industry standards.

ProcessMaker - ProcessMaker is an easy to use BPM and workflow software solution. It is used to design, automate, and deploy business processes of any kind.