If youre a geek, you know what HTTP is. If youre not, youve still seen those letters, lurking at the front of URLs everywhere. Its one of the two or three things that makes the Web actually work. Its being redesigned, perhaps. This telling of the story is mostly for geeks, but for the rest: If this effort is successful, you might notice some things run a little quicker. If it fails, you might notice some things running slower, or getting more expensive, and the Net growing a little less private and safe.
Back Story
When we talk about HTTP versions we use slashes: HTTP/0.9, HTTP/1.0, HTTP/1.1, and so on. The first version to see the light of day was HTTP/0.9. By the time the Web became popular, wed mostly managed the transition to HTTP/1.0. HTTP/1.1 was specified in 1996, and has been widely implemented, but Id say it hasnt been as much of an improvement on HTTP/1.0 as people hoped for.
But still, no matter how you measure it, HTTP has been the most successful application protocol ever invented, by a wide margin.
Theres long been discussion of HTTP over at the IETF, but over the course of the last year, theres been a formal launch of a process aimed at delivering HTTP/2.0.
HTTPs Dirty Secret
The vast majority of application traffic across the Internet, including HTTP, has historically been based on the TCP protocol, which allows a program on one computer to establish a connection to another on another, and interchange arbitrary data. Two things about TCP connections turn out to be important. First, theyre kind of expensive and slow to set up (but reasonably cheap and efficient once theyre running). Second, they dont last forever; on a global scale, the network is a fragile thing, and eventually, your connection will go down.
It turns out to be really hard to design applications to use the Net in a way that works around connections that arbitrarily break under you. It also turns out that HTTP neatly solves the second problem, and lets you build Web apps that scale beautifully and degrade gracefully; but the solution involves making tons and tons and tons of different TCP connections. HTTP is a poor citizen of the TCP-centric Internet.
This has driven the IETF greybeards crazy for decades, but theyve gotten no relief, because HTTPs application-level advantages are so huge that its being used for more and more and more every day. Which includes that slick little smartphone in your pocket; If HTTP were a better Internet citizen, your battery might last longer.
The HTTP/2.0 process.
Theyre working on their objectives, but I think its fair to say that two dominate: Better performance on the TCP-based Internet, and better security, where security is a big multi-dimensional word referring to several different big multi-dimensional problems.
There is a back story here, and its spelled SPDY . This is a drop-in replacement for HTTP networking that should be invisible to both clients and servers. It was cooked up at Google, and is built into Chrome and Firefox, and a lot of the servers at Google use it. It may be relevant that Mike Belshe, whos sort of seen as the guy behind SPDY, used to work for Google but doesnt any more.
The State of Play
I could go on and on about the proposals and what people are saying, but I think readers here who actually care shouldnt listen to me, they should consult the primary references. So:
The mailing list where discussion happens, from which:
Expressions of interest from: Alibaba, curl, Facebook, Firefox, Google, haproxy, Jetty, Microsoft, Squid, Twitter, and Varnish.
This should be fun to watch.