[Groxx]

To +1 this: yes, they clearly share a lot of code, and have mostly-identical plug-in interfaces, and many dedicated IDEs have plugins for the more-general Intellij IDE.

And they present them as "just" a dedicated UI around the plugins.

But no, they are not actually the same. Essentially ever. The dedicated IDEs often have features that never make it into their plugins, and a lot of the UX and project structure/preferences/etc are quite specialized and don't always have equivalents outside it. You get like 90-95% with the plug-in, but not 100%, and sometimes that's a critical difference.

The plugins do have the distinct benefit of allowing you to use multiple in a single project, though.