Tempstream is a small but powerful library that makes it easy to use HTML streaming in your app. It lowers the TTFB metric and generally makes the website load much faster, thanks to the fact that we give browser opportunity to do stuff before the entire HTML of the website is finished generating.
Thanks to @FilipI it has recently gained support for JSX syntax, making it more familiar to React developers and hopefully making the switch to Server Side Rendering easier
Some links: