"Diagramly is a free online diagram drawing application. You can use it to create UML, entity relationship, org charts, BPMN and BPM , database schema and networks. Also possible are telecommunication network, workflow, flowcharts, maps overlays and GIS, electronic circuit and social network diagrams. It's like a mini version of Visio in your browser.
You can export your diagram in our raw XML format, PNG or JPG, or as SVG. When reloading you can load back up the XML you saved previously, or import Visio. vdx.
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The grid system generator will create fixed grid systems in valid css / xhtml for rapid prototyping, development and production environments *.
In addition to the css framework, it creates a background file (sample) that you can use in Fireworks, Illustrator, OmniGraffle, Photoshop, Visio (etc.) to aid in prototyping and design.
Don't waste your afternoon drawing UML Sequence Diagrams.
Just enter the description here, and click "draw". The SD/MSC Generator is an easy alternative
to using mouse-centric tools like Microsoft Visio.