Why we still use HTTP is beyond me. And I don't mean about the speed issues. Why have a protocol that's so complicated when most of the things we need to build with it are either simpler or reimplement parts of the protocol.
Minimal implementations of HTTP (and I'm strictly talking about the transport protocol, not about HTML, JS, ...) is dead simple and relatively easy to implement.
Of course there's a ton of extensions (gzip compression, keepalive, chunks, websockets, ...), but if you simply need to 'add HTTP' to one of your projects (and for some reason none of the existing libraries can be used) it shouldn't take too many lines of code until you can serve a simple 'hello world' site.
On top of all that, it's dead simple to put any one of the many existing reverse proxies/load balancers in front of your custom HTTP server to add load balancing, authentication, rate limiting (and all of those can be done in a standard way)
Furthermore, HTTP has the huge advantage of being readily available on pretty much every piece of hardware that has even the slightest idea of networking. Any new technology would have to fight a steep uphill battle to convince existing users to switch.
Have I mentioned that it's standardized and open?
(I'm speaking about authenticated connections. For anonymous access - which should be read-only anyway - you're usually better off using HTTP anyway)
So in that case, at least, I was very glad FTP(S) was still around.
FTP does have some advantages, but HTTP has more advanced support for resuming connections, virtual hosting, better compression, and persistent connections, to name a few.
I bet if we had used FTP instead of HTTP for serving HTML right from the start, FTP would today have all of the same extensions and the same people would argue for it being too bloated :) (HTTP started as pretty minimalistic protocol back in the day)
I often find the discrepancy between what HTTP has originally been designed for (serving static HTML pages) and all the different things it's being used for today highly amusing. Yes, some of todays applications for HTTP border on abuse, but its versatility (combined with its simplicity) fascinates me.
The two success factors of http are statelessness and fixed verbs.
http://i3.kym-cdn.com/photos/images/original/000/732/170/796...
HTTP is quite a good protocol. Simple, extensible to a sane extent, but not overly extensible (XMPP i'm thinking about you). HTTP is not accidentally successful. FTP is a bad joke. (stateful. binary mode, 7 bit by default. uses multiple connections (unless in passive mode))
Which are dead simple to construct, send, receive and parse.
Really.
For example, let's curl -L (view everything but the body) for the spec: http://www.ietf.org/rfc/rfc7230.txt
HTTP/1.1 200 OK
Date: Tue, 24 Jan 2017 12:00:55 GMT
Content-Type: text/plain
Transfer-Encoding: chunked
Connection: keep-alive
Set-Cookie: __cfduid=df57c7720b704a40e4c3367bbe248771c1485259254; expires=Wed, 24-Jan-18 12:00:54 GMT; path=/; domain=.ietf.org; HttpOnly
Last-Modified: Sat, 07 Jun 2014 00:41:49 GMT
ETag: W/"3247b-4fb343e4dcd40-gzip"
Vary: Accept-Encoding
Strict-Transport-Security: max-age=31536000
X-Frame-Options: SAMEORIGIN
X-Xss-Protection: 1; mode=block
X-Content-Type-Options: nosniff
CF-Cache-Status: EXPIRED
Expires: Tue, 24 Jan 2017 16:00:54 GMT
Cache-Control: public, max-age=14400
Server: cloudflare-nginx
CF-RAY: 326353e6a6a257a7-IAD
A bunch of newline, (CRLF), seperated key-value mappings. Some with a DSL (Such as Set-Cookie).
It gives you a status message instantly, a date to check against cache, a Content-Type for your parser, acceptable encoding, for your parser, a bunch of other values for your cache. All for free.
As for the body of the content? For a gzipped value like this, it's everything outside the header, until EOF. That's not quite as easy as when the content-length parameter is given, but hardly difficult for parsing.
HTTP is easy.
In fact, HTTP is so easy, that in-complete HTTP servers can still serve up real content, and browsers can still read it.
HTTPS is more complicated, but if you simply rely on certificate stores and CAs, it becomes much easier, but HTTPS is a different protocol.
This is chunked and keep- alive. Things get a little trickier