After doing some research I've found that there's no ready made solution that we could use (or at least was future proof for upcoming Playnite features). We will have to implement our own.

The temporary solution for now will be opening special sub-forums on official forum #430 until the gallery is complete.

I can make the frontend for it, as I am unsure what backend language you're using right now and I can't be arsed to learn another language.

Thanks for the offer, but I've postponed this indefinitely, because there are more important and more useful features to be added. I'll be launching new forums soon that should act as extension gallery in the mean time.

As a temporary 0-cost alternative, might I suggest a simple public-wiki-style .md file, like this?

As a temporary 0-cost alternative, might I suggest a simple public-wiki-style .md file, like this?

I started a repository to do exactly that, since it looks like there hasn't been any progress on this issue. Feel free to contribute any extensions I might have missed! Extensions and themes are a bit difficult to find and curate, which underlines the need for some resolution of this issue.

There will be add-on database integrated into Playnite 9, similar to how how winget does it (add-on manifests stored in special repository with custom add-on broswer in Playnite itself).

Awesome, that sounds like a great solution. Will the special extension repository be publically accessible in .git land, or will the implementation be something else?

It will be literally a git repository. As I said, very similar to how winget does it.

I assume this issue is resolved now with the release of Playnite 9?

No it wasn't, we still don't have a web page to browse add-ons.