This is awesome! As nice as it is to be able to edit right inside the original page, from my perspective the fact that math is rendered in the embedded version is an even bigger improvement! I look forward to using it on my own site.
In order to try it out, I did navigate to one of the Demo topics that you linked and noticed a few small issues when responding there:
- The Markdown/Rich editor toggle did not appear in the editor toolbar,
- After posting, I attempted to edit the post at the site and received a warning that the post was being edited in another window, though I had no other window opened in which to edit it, and
- I was unable to delete my reply. Evidently, it was deleted by the community.
Overall, though, a huge step - thanks!