Amazon Silk is a web browser developed by Amazon for Kindle Fire line of tablets and Fire Phone. It uses a split architecture whereby some of the processing is performed on Amazon's servers to improve webpage loading performance. It is based on the open sourceChromium project.
For each webpage, Silk decides which browser subsystems (e.g. networking, HTML, page rendering) to run locally on the device and which to run remotely on the Amazon EC2 servers.
Silk uses Google's SPDY protocol to speed up the loading of web pages. Silk gives SPDY performance improvements for non-SPDY optimized websites if the pages are sent through Amazon's servers. Some early reviewers found that cloud-based acceleration did not necessarily improve page loading speed, most notably on faster connections or for simpler web pages.
Some privacy organizations raised concerns with how Amazon passes Silk traffic via its servers, effectively operating as an Internet service provider for those using the browser. The Silk browser includes the option to turn off Amazon server-side processing.
Amazon says "a thread of silk is invisible yet incredibly strong connection between two different things", and thus calls the browser Amazon Silk as it is the connection between Kindle Fire and Amazon's EC2 servers.