To embed a chat group, you will need to know the chat's name ONLY.
To embed YouTube videos, you need to copy the video URL then paste it on the input.
xat recommends the embedding of radios via the service xatRadio.
You can embed a Facebook Page and its posts and/or likebox.
You can embed a Twitter profile on your xat.me and chat groups.
You can use some things like a Globe or Viewcounter. It's not affialited to xat.
You can embed a bubble shooter game on your xat.me and chat groups.
You can use fonts directly from Google Fonts, using a simple BBcode.
You can use this tool to generate a player in real time to your chat and xat.me.