Quick and dirty userscript that inlines footnotes so I don't have to scroll to the bottom and up again.

safari-inline-footnotes.js

// ==UserScript==
// @name         Safari Books Online
// @namespace    https://www.safaribooksonline.com/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://www.safaribooksonline.com/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    setTimeout(function() {
        var pointers = document.querySelectorAll('.totri-footnote');
        console.log(pointers);
        for(var i = 0; i < pointers.length; i++) {
            var pointer = pointers[i];
            var fnId = pointer.href.split('#')[1];
            console.log(fnId);
            var fnText = document.querySelector('#'+fnId).innerHTML;
            console.log(fnText);

            var el = document.createElement('em');
            el.innerHTML = fnText;
            pointer.parentElement.parentElement.appendChild(el);
        }
    }, 1500);
})();