> Do any other languages have the same kinds of optimisations that PHP has with FPM where it keeps the process alive but pretends it's a complete fresh execution at the language level?
I'm not aware of other languages where it is baked into a language itself, but FastCGI libraries tend to be basically drop-in replacements for CGI ones (at least it's the case with common C, Perl, and Haskell libraries; sometimes CGI and FastCGI libraries are combined, so that they are usable in either setting): you get the optimization, while still can pretend that it's a regular CGI. I guess the primary difference from PHP is just that global/static variables would survive.
I'm not aware of other languages where it is baked into a language itself, but FastCGI libraries tend to be basically drop-in replacements for CGI ones (at least it's the case with common C, Perl, and Haskell libraries; sometimes CGI and FastCGI libraries are combined, so that they are usable in either setting): you get the optimization, while still can pretend that it's a regular CGI. I guess the primary difference from PHP is just that global/static variables would survive.