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, .
diagrams.net vs SmartDraw opinions
Smartdraw allows automatic addition of blocks in flowchart in a simpler and with less clutter than draw.io
Good alternative for circuit diagrams and SLD for electrical networks.
Dia is a GTK+ based diagram creation program for Linux, Unix, Mac OS X and Windows released under the GPL license.
Dia vs SmartDraw opinions
Draw lets you produce anything from a quick sketch to a complex plan, and gives you the means to communicate with graphics and diagrams. With a maximum page size of 300cm by 300cm, Draw is a an excellent package for producing technical drawings, general posters, and much else.
Pencil is a standalone app that lets you create diagrams or UI mockups. It doesn't have collaboration/multi-user features.Discontinued
The last release/commit was in October 2019.
Pencil Project vs SmartDraw 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...
yEd Graph Editor vs SmartDraw opinions
colourful and looks professional
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.
Creating flowcharts, organizational charts, business diagrams, science illustration, network diagrams, mind map and lots more.
An online diagramming tool with built-in productivity features to create diagrams faster. Draw flowcharts, mind maps, org charts, network diagrams, Venn diagrams and 50+ other diagrams types. Readymade templates to get started fast.