My company website has ended up being a bit of a testbed for trying new things, and the latest thing I updated was adding HTTP/2 support.

HTTP/2 is the new HTTP protocol, which should lead to various performance boosts and other various nice things. As it turns out, the server I'm using - Nginx - has built-in support for HTTP/2, which makes enabling it incredibly easy.

You'll need to already be using https/SSL, since most browsers will only support secure HTTP/2 connections, but the main step is to just upgrade Nginx to the latest version (> 1.9.5):

sudo apt-get update
sudo apt-get install nginx

Next, update the Nginx conf for your site by adding the http2 tag to the server block:

server {
    listen 443 ssl http2 default_server;    # http2 added here

    ssl_certificate    server.crt;
    ssl_certificate_key server.key;
    ...
}

Finally just restart Nginx: sudo service nginx restart, and check using an extension or similar.