 The second-generation Kindle Fire HD runs a customized Android 4.0.3 Ice Cream Sandwich OS.Along with access to Amazon Appstore, the Fire includes a cloud-accelerated "split browser", Amazon Silk, using Amazon EC2 for off-device cloud computation; including webpage layout and rendering, and Google's SPDY protocol for faster webpage content transmission.The user's Amazon digital content is given free storage in Amazon Cloud's web-storage platform, 5 GB music storage in Amazon Cloud Drive, and a built-in email application allows webmail (Gmail, Yahoo!, Hotmail, AOL Mail, etc.)