Create UML diagrams online in seconds, no special tools needed.

yUML is a tool that uses the URL to generate a diagram on the fly.

Here is an example:

<img src="http://yuml.me/diagram/class/[Customer]<>1-orders 0..*>[Order], [Order]++*-*>[LineItem], [Order]-1>[DeliveryMethod], [Order]*-*>[Product], [Category]>->[Product], [DeliveryMethod]^[National], [DeliveryMethod]^[International]"/>

Gives you:



The technology behind it appears to be Ruby on Rails, which begs the question "will it still be useful when it gets overused?", lets hope there is a cloud waiting to host it, because this could really take off.