The question arose - in The Loop chat - because Automattic now acquired Woocommerce. Personally I don't think that this makes Woocommerce a first party plugin. We don't consider all those other Automattic plugins automatically on topic, right? Besides - in my mind - the question of first or third party has to be mainly answered from the perspective of the asker. But enough talk: What are first party plugins?
Automattic's business and properties are irrelevant to our scope.
The only first party plugins would be those that are part of WordPress org project.
As of right now that would be:
- plugins which are de-facto part of core experience, such as native importer
- feature plugins, slated for core inclusion
I think we had historically treated BuddyPress and bbPress as such too, but their current status as part or not part of org project is murky, to my knowledge.
Worth mentioning that some projects seem to be commonly accepted in scope due to their unique role or functionality. WP CLI comes to mind, despite not being org project it's uniquely important for managing WP in command line environment.
As an Automattician, and one who's just acquired a large number of new colleagues, I would say no.
Most of the Jetpack is first party crowd are working under the assumption that WordPress is an Automattic venture, built by and for Automattic and opensourced out of their kindness, which as most of us know is false.
The only first party plugin I would consider is Hello Dolly, first party themes being the default themes. Otherwise the whole concept of first party is meaningless for our purposes and has no use
That's an oxymoron: The first party is the WordPress core, the second is you, the developer. So there are just second-party plugins (besides Hello Dolly) which are on-topic and third-party plugins, made by others, which are currently not on-topic. I think, they should be, but that's another question …
As long as WooCommerce is not part of the core or the asker is not one of its core developers, it is third-party.