Custom editor DLLs

I have created a custom editor that I would like to submit to the asset store shortly. I would like to provide my product as a DLL.

Do I need separate DLL’s for editor and runtime?

What is the easiest way to create and manage the DLL project?

Yes, when compiling .DLL you should separate all code that’s using UnityEditor since it’ll be left out of the build. You may have different libraries, or make your editor scripts as Content so they’re not pre-compiled into the library.

As for creating and managing .DLL, I don’t know of any way aside using Visual Studio’s awesome build pipeline.

Now this is just opinion, and I’m also a fan of library since it allows to group scripts and obfuscate code, but for the same reason, I’d believe the AssetStore users tend to favor separate scripts, you may want to consider providing sources or something.