Apple released Safari 5 on June 7, 2010, featuring the new Safari Reader for reading articles on the web without distraction (based on Arc90's Readability tool), and a 30 percent JavaScript performance increase over Safari 4. Safari 5 includes improved developer tools and supports more than a dozen new HTML5 technologies, focused on interoperability. Since Safari 5, developers can create secure Safari Extensions to customize and enhance the browsing experience. Apple also re-added the progress bar behind the address bar in this release. Safari 5.0.1 enabled the Extensions PrefPane by default; previously, users had to enable it via the Debug menu.