Serviio

I have checked inside the package contents of the app and also Application Support--> Serviio-Console-Wrapper but I do not see any folders such as javascript or plugins.

Loving Serviio so far. Works great with my Denon AVR

When Serviio is installed, it creates a folder structure, and one of the folders is labeled plugins. But the only plug-ins that go there are specifically for Serviio. Your OS shouldn't have need for anything in there. Plug-ins are generally used for parsing online streams from particular sites. As for Javascript, I don't see any specific folder for that. Serviio is written in Java, and there are dozens of jar files in the Serviio/lib folder.

If you don't need a plug-in for a specific online source, that folder can just remain empty. There's a read-me file in mine, but that's it.

I was considering trying a few plugins, that’s what got me looking. But there is no plugins folder that I can see. Should I just create it, and if so, where should it go?

I don't know where it's installed within the Mac OS file structure, but wherever the Serviio home folder is located you should be able to create a plugins folder. That's the name and case for the folder on my PCs. So just create a plugins folder under the Serviio home folder and it should be fine. You can see in the Serviio log if it loads any plugins when it starts. It loads all plugins at startup, not when they are used, so it should be early in the log.