Requiring some sort of VM or container to run this webserver on? Is it possible that's way more onerous than a static html file which can be emailed around? Are you sure nginx is even going to be around in, say, 15 years? (think password protected PDF but in html and allowing for JavaScript.)

> you sure nginx is even going to be around in, say, 15 years?

Considering it's been around longer than that, yes I think it will be around in 15 years