Hariette is hard at work to create an alpha release that is stable enough to start rolling out. Follow https://kbin.social/m/ArtemisApp (!ArtemisApp@kbin.social for you Lemmy users) for more updates and announcements on the app.
Hariette is also available at kbin: @hariette, and Mastodon: @hariette.
As of right now it is not open source, but @hariette is leaning towards open source upon public release Source from the Artemis App discord.
I really hope that is the case, I wouldn’t be on board with swapping my open source reddit app for a proprietary fediverse one.