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 kinds of diagrams online. Developed by Gliffy, Inc.
License: Freemium
Pencil Project is an open-source tool that excels in creating wireframes and mockups with a user-friendly interface, while Gliffy is a cloud-based diagramming tool known for its real-time collaboration and extensive shape library. The choice between them depends on whether you prefer a free, customizable solution or a more polished, collaborative environment.