Tools for creating Class Diagrams [closed]
Solution 1:
I use GenMyModel, first released in 2013. It's a real UML modeler, not a drawing tool. Your diagrams are UML-compliant, generate code and can be exported as UML/XMI files. It's web-based and free so it matches your criteria.
Solution 2:
I used Poseidon UML Community Edition, it's platform independent and makes fine and clean diagrams. There are some screenshots here.
Solution 3:
A nice online tool: yUML
Solution 4:
Some time ago I used DIA - free and platform-independent. It was ok. Now I use Enterprise Architect but it's not free.
Solution 5:
I always use Gliffy works perfectly and does lots of things including class diagrams.