I was unfamiliar with this stack and had an AI conversation about it to figure out what it meant, if I'm correct (not likely), this openrun+Go stack has a PHP FastCGI analogy:

Your web app can be HTML templated pages, with HTMX client interactivity and server interactivity provided by ~~PHP~~ Starlark, which does not have full OS access, but only what ~~CGI~~ OpenRun exposes as possible functionality, all of which happens in-process and per web route.

That's a fascinating new combination!