Internet Explorer 11 is featured in Windows 8.1, which was released on October 17, 2013. It includes an incomplete mechanism for syncing tabs. It is a major update to its developer tools, enhanced scaling for high DPI screens, HTML5 prerender and prefetch, hardware-accelerated JPEG decoding, closed captioning, HTML5 full screen, and is the first Internet Explorer to support WebGL and Google's protocol SPDY (starting at v3). This version of IE has features dedicated to Windows 8.1, including cryptography (WebCrypto), adaptive bitrate streaming (Media Source Extensions) and Encrypted Media Extensions.