Discourse is a popular open-source forum software that this community happens to run on.
Discourse has a system called Oneboxing for turning URLs into previews.
For example, here is what the onebox for this URL
https://github.com/discourse/onebox looks like:
I am proposing a feature request to add onebox support for plotly embed URLs, like this one: https://plot.ly/~empet/14234.embed
That way, the above URL will be transformed into a live plotly graph, and bob’s your uncle.