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.
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...
Dia is a GTK+ based diagram creation program for Linux, Unix, Mac OS X and Windows released under the GPL license.
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.
Google Drawings, part of Google Drive, allows users to collaborate creating, sharing, and editing images or drawings. It can be used for creating charts, diagrams, designs, flow-charts, etc.
Draw, part of the Apache OpenOffice suite, is a graphics editor that gives you the tools to communicate with visuals and diagrams. With a maximum page size of 300cm by 300cm, Draw is powerful tool for posters, graphs, charts, and more.
Core2D is a multi-platform application for making data driven 2D diagrams. The application has built-in wyswig vector graphics editor where you can bind data to shapes, share data across multiple documents, edit documents using layers.
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.
Instead of starting with a blank screen, SmartDraw gives you the exact template you need. Then use simple commands to add your information and SmartDraw does the rest. There's no other drawing software like it.
ConceptDraw DIAGRAM v14 is the only product that supports Visio legacy, runs on macOS and Windows, and is a perpetual license. Import/Export VDX, VSDX, VSSX and Import VSD, VSS files.