Many people do not seem to know about the onebox feature Discourse has. When you want to paste a link to youtube or similar, if you paste the link on a separate line by itself then Discourse renders the video in place and you cam play it in situ. The web interface composition window will show the preview. Discourse is a very sophisticated environment.
Not only that, it looks great, and is so convenient.
When people forget I’ll take the liberty of editing the post to do this.