UMLGraph
draw.io
Dia
LucidChart
yEd
OmniGraffle
UMLet
CollabNet
VitoDeploy
Ploi.io
UMLGraph
VitoDeploydraw.io - Online diagramming application
Ploi.io - Stop the Hassle. Start deploi'ing. Use Ploi.io for easy site deployments. We take all the difficult work out of your hands, so you can focus on doing what you love: developing your application.
Dia - Dia is a GTK+ based diagram creation program for GNU/Linux, MacOS X, Unix, and Windows, and is released under the GPL license.
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
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.
OmniGraffle - OmniGraffle is for creating precise graphics like website wireframes, an electrical system designs, or mapping out software class.