SPDY is a replacement for HTTP, designed to speed up transfers of web pages by eliminating much of the overhead associated with HTTP. SPDY supports several optimizations that give it an edge over HTTP when it comes to speed. SPDY is gaining a great deal of traction — it has been implemented in Chrome, Firefox, and Amazon Silk, has been deployed widely by Google, and there is now SPDY support for Apache through the mod_spdy module.