I have a chatroom where I advertise interesting posts that I come across on Mathematics SE:
Feel free to drop by! :) Anyone is welcome to share in my room interesting posts on this site that they come across, too. A short blurb to accompany a link is recommended, but not mandatory.
A new SE site for Proof Assistants has been recently proposed, do check it out! If you find it interesting, you can add your support to the proposal by committing to it. :)