UML Designer - UML Designer provides a set of common diagrams to work with UML 2.5 models.
Cisco Packet Tracer - Download Cisco Packet Tracer, an innovative network simulation and visualization tool used by Cisco Networking Academy students and instructors.
Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)
GNS3 - GNS3 is a graphical network simulator that allows simulation of complex networks.
ARIS Express - ARIS Express is based on the proven ARIS methodology and industry standards.
Paessler Multi Server Simulator - Paessler Multi Server Simulator is inexpensive and robust software that helps you power massive-scale testing.