Cacoo is a user friendly online drawing tool. Multiple users editing the same diagram means Real-Time Collaboration.

Creately is a collaborative diagramming and design software used by teams around the world to communicate more effectively.

Diagram Designer is a vector graphics editor that allows you to create UML class diagrams, illustrations, flowcharts and slide shows.

Diagrammix is a tool for efficiently building attractive diagrams and flowcharts.

Edraw Max is comprehensive mind mapping and planning tool network diagrams, floor plans, workflow diagrams, business charts, and engineering diagrams.

CmapTools is concept mapping software.

ConceptDraw PRO is diagramming software used to create business graphics, including ConceptDraw Flowcharting Suite.

Dia is free and open source drawing software.

draw.io is free online diagram software for making flowcharts, process diagrams, etc

Diagramo is an online flowchart software. It's FREE and Open Source ( GPL ) It's pure HTML5 Share and collaborate.

Gliffy is software for diagramming via a HTML5 cloud-based app. It is used to create UML diagrams, floor plans, Venn diagrams, flowcharts and various other ki…

LibreOffice is a full-featured office productivity suite that provides a near drop-in replacement for Microsoft Office.