IEEE Internet Computing

Device manufacturers, users, and authors have differing needs and expectations when it comes to Web content. Web software and hardware manufacturers naturally try to differentiate their products by supporting a special combination of capabilities, but few can expect Web authors to create content for their product alone. Users, however, do expect to access the same content from any device with similar capabilities. Even when device capabilities differ, users might still want access to an adapted version of the content. Due to device differences, the adaptation might not produce an identical presentation, but device-independence principles suggest it should be sufficiently functional to let users interact with it successfully. Web application authors cannot afford to create multiple content versions for each of the growing range of device types. Authors would rather create their content once, and adapt it to different devices-but they also want to retain control of presentation quality. Device independence is about trying to satisfy these differing needs, spanning the delivery path between author and user by way of diverse manufacturers' devices. The field's continued evolution within the broader Web standards framework aims to find solutions that are beneficial for all.

When we launched the Akamai system in early 1999, it initially delivered only Web objects (images and documents). It has since evolved to distribute dynamically generated pages and even applications to the network's edge, providing customers with on-demand bandwidth and computing capacity. This reduces content providers' infrastructure requirements, and lets them deploy or expand services more quickly and easily. Our current system has more than 12,000 servers in over 1,000 networks. Operating servers in many locations poses many technical challenges, including how to direct user requests to appropriate servers, how to handle failures, how to monitor and control the servers, and how to update software across the system. We describe our system and how we've managed these challenges.