Firefox 36 provides security fixes and improvements, and is the first version of Firefox to fully support the new HTTP/2 protocol.
HTTP/2 is the successor to HTTP 1.1, the protocol on which the Web has run since 1999. On Feb. 18, Mark Nottingham, chair of the IETF HTTP Working Group, declared that HTTP/2 is done—meaning the basic definition of the HTTP/2 protocol has been finalized and now the specification is going through the final phases of the standards process. Multiple improvements were made to HTTP/2 to make network transport more efficient and more secure than the current HTTP 1.1 protocol.
Mozilla’s Firefox 36 release notes refer to HTTP/2 as enabling “a faster more scalable and more responsive web.”