1. 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.

  2. OmniGraffle is for creating precise graphics like website wireframes, an electrical system designs, or mapping out software class.

  3. Online diagramming application

  4. Simplify and communicate complex information using data-linked diagrams.

  5. PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.

  6. Dia is a GTK+ based diagram creation program for GNU/Linux, MacOS X, Unix, and Windows, and is released under the GPL license.

  7. 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.

  8. Gliffy is a powerful HTML5 online diagram maker. Create a flow chart, network diagram, UML diagram, organizational chart or wireframe with ease.

  9. The prototyping and specification software used by 87% of the Fortune 100. Beyond mockups, design interactive prototypes for business solutions, websites, and applications.

  10. StarUML

  11. Balsamiq. Rapid, effective and fun wireframing software.

  12. Professional digital design for Mac.