
UMLGraph
draw.io
Dia
LucidChart
yEd
OmniGraffle
UMLet
CollabNet
Python Studio
PyCharm
IntelliJ IDEA
UMLGraph
Python Studiodraw.io - Online diagramming application
PyCharm - Python & Django IDE with intelligent code completion, on-the-fly error checking, quick-fixes, and much more...
Dia - Dia is a GTK+ based diagram creation program for GNU/Linux, MacOS X, Unix, and Windows, and is released under the GPL license.
IntelliJ IDEA - Capable and Ergonomic IDE for JVM
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.