Flagship

A flagship product is a product or service by an entity—typically an organization, be it for-profit or non-profit—that is intended to demonstrate the entity's capabilities.

In the case of the Fediverse, an example flagship product would be a running instance of a specific Fediverse software by the creators of said software.

As an example, the Mastodon organization not only distributes the Mastodon software, but also hosts a copy of it