diagrams.net (previously draw.io) is a free online diagram drawing application for workflow, BPM, org charts, UML, ER, network diagrams. No login or registration are required and features include the ability to save locally (including SVG), a range of stencils, .
Dia is a GTK+ based diagram creation program for Linux, Unix, Mac OS X and Windows released under the GPL license.
Dia vs Umbrello opinions
yEd is a powerful diagram editor that can be used to quickly create diagrams manually or import external data for analysis and auto-magically arrange even large data sets by just pressing a button. You can use yEd to quickly create flow charts, BPMN and UML diagrams...
PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams. The generator can be run anywhere within JVM and integrated with various application such as wiki, text editor, IDE, programming language, documentation generator, and others.
OmniGraffle can help you make eye-popping graphic documents—quickly—by providing powerful styling tools, keeping lines connected to shapes even when they’re moved, and magically organizing diagrams with just one click.
Creating flowcharts, organizational charts, business diagrams, science illustration, network diagrams, mind map and lots more.
Visual Paradigm for UML (VP-UML) is a UML design tool and UML CASE tool designed to aid software development. VP-UML supports key modeling standards such as Unified Modeling Language (UML) 2.4, SysML, ERD, DFD, BPMN 2.0, ArchiMate 2.0, etc.
StarUML is a program to develop fast, flexible, extensible, featureful, and freely-available UML/MDA platform running on Win32 platform. The goal of the StarUML project is to build a software modeling tool and also platform that is a compelling replacement of commercial UML...
MyDraw is an easy to use, yet powerful diagramming software that lets you create a large number of diagrams like flowcharts, organizational charts, mind maps, network diagrams, floor plans, family trees, business model diagrams, and many more.