I can volunteer to build or help build such a site. I think such a site should have examples of apps built with JavaFX or/and big well known companies using JavaFX to build apps. For example we can say that NASA uses JavaFX or at least that NASA uses software built with JavaFX (just an example). Electron, React Native, Xamarin have this on their website. I think it acts a bit like the movie scores on sites like IMDB that you check out before actually seeing the movie to know if the movie is any good. It shows proof that you can build real, well working apps with JavaFX. If reputable companies use it or reputable software has been built with it then it should be good.
Another point: If the site is to have a highly interactive component with list of third party libraries, tweets, blog posts, etc. Then it needs to be actively maintained or we risk passing down the message that the technology is dead. If all those links are old, obsolete or broken or the user sees that no new content has been added in a while, he may assume the technology isn't being maintained. So if we add this we need to make sure it can in fact be actively maintained. One other question I'd like to raise is the domain. What domain should we use? Cheers, -- Pedro Duque Vieira - https://www.pixelduke.com