This code runs on api.iconify.design that is used to serve collections and SVG images.
PHP version is available at https://github.com/iconify/api.php
To start server simply run
node app
By default server will be running on port 8084. You can change port and other configuration by adding custom config.json
File config.json is the same as config-default.json, but contains only values you have customized. See config.md
It is better to run server on obscure port such as 8084 hidden behind firewall and use nginx reverse proxy. This way you can offload connection handling to nginx and you can easily use SSL, rate limiting and other security features nginx provides.
Node.js version of server is faster because it loads everything only once on startup. It is a bit harder to setup though because you need to install additional software and make sure server is running (using tools such as "pm2").
PHP process ends when HTTP request ends, so PHP has to reload lots of things for each request. PHP version has caching to minimize loading times, but it is still nowhere near as fast as Node.js version. The only upside of PHP version is it is easy to setup - simply upload files and you are done.
Node.js version has one feature that PHP version does not have: ability to send errors by email.
Use Node.js version if you can for better performance and better error reporting.