I just noticed it has been a while since my original post, so, first and foremost, welcome to all (relative) newcomers in this thread. Great to see the Nova extension ecosystem thriving!
Now for a little update about my activities. I currently maintain the JXA (JavaScript for Automation – niche) and µESLint (ESLint taken minimally – very niche, you probably want Cameron’s) extensions, both due for an update.
For the last year, I have been working, on and off, on a full featured extension for fish shell scripting. Partly because this has proven to be a bit more complex than I originally fathomed, I have lately been on a side quest building a foundation for my, and hopefully other’s, extensions, in the form of a meta-extension tentatively titled NovaNova, which will combine a function and abstraction library for extension development with in-Nova-runtime unit testing facilities based on QUnit (with the library being tested and the testing integration built with the library, this is an ultimate circular dogfooding squad thingagummy).