There is a cool diagramming tool for IntelliJ IDEA powered by yFiles. Check out this video: https://youtu.be/cTg_ocVFmcs?t=36
I wonder if I can get this thing to work on IntelliJ IDEA (Community Edition). The problem is there is no such plugin available in the plugins repo. How to perform the setup?
The community edition only supports a limited number of plugins. The class diagram plugin is only supported in the Ultimate edition if I remember correctly.
You can always try a 30-day free trial of IntelliJ Ultimate (or RubyMine).