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How to create http server in browser using javascript?

I am implement html5 player. It is similar to streaming, but it is not strictly streaming.
First I tried.
Using Media Source Extensions.
But I can not implement seeking. I do not know the byte offset.
So I thought.
If you can create an http server in your browser, I can only respond to range requests.
Can I create http server in browser using javascript?
It is support mobile/pc browser.
It is must support mobile/pc browser.

Can I create http server in browser using javascript?
No. Regular browser Javascript cannot create a web server. Browser Javascript was not given that capability and since you cannot create your own TCP server either, you cannot even build your own http server.
To do something like that, you'd have to have a browser extension that used some native code to set up an http server. But, even if you did that, you'd probably have firewall issues since most clients are not directly reachable by other clients unless they happen to be on the same sub-network as clients are usually behind a firewall.

Script on server to interact with clients Javascript

I currently have a javascript library that is using a JSON file to print them on the screen in an interactive way. (::We are using D3JS Library)
When we are on a client, we can easily delete, edit and create some nodes, that are updated in the JSON every 5-10 seconds.
The problem comes from two main facts :
First the automatic function that call itself every x seconds could make data corruption if we are doing some stuff on the datas already represented on the screen.
Then the project has been made in order to permit 5 people to interact together. When they are present onto the same session we cannot decently make them refresh every 5 seconds, that cause many overhead and doesn't avoid data corruption.
We have mainly thought about a solution only made with javascript and some AJAX but we realize that it should be reconsidered with a trigger that inform the client that the datas are no longer OK.
We are thinking currently about opening a script onto a server in order to attribute on each client an ID.
The goal would be to detect the modification done on the JSON file (on the server). But the point where we are stuck is :
1) Is there a best scripting language to interact server/web?
2) Which type of things should we use to make the clients update their datas? (socket right?)
About the second point the easiest way would be to call a JS function be we aren't aware of the possibilities given by the shell codes...
Sorry about the fact that we are happy developpers but maybe not enough skilled to solve this problem.
Thanks for your helps !

You can achieve that using pure javascript with the new WebSocket feature.
http://www.html5rocks.com/en/tutorials/websockets/basics/
Edit:
WebSocket is a web technology providing full-duplex communications channels over a single TCP connection. The WebSocket API is being standardized by the W3C, and the WebSocket protocol has been standardized by the IETF as RFC 6455.
WebSocket is designed to be implemented in web browsers and web servers, but it can be used by any client or server application. The WebSocket Protocol is an independent TCP-based protocol. Its only relationship to HTTP is that its handshake is interpreted by HTTP servers as an Upgrade request.[1] The WebSocket protocol makes possible more interaction between a browser and a web site, facilitating live content and the creation of real-time games. This is made possible by providing a standardized way for the server to send content to the browser without being solicited by the client, and allowing for messages to be passed back and forth while keeping the connection open.

Ajax simple question

I have a very simple question about ajax.
If I'd like to refresh a particular area of my site I supose ajax would be the best way.
But is there anyway instead of having a javascript periodically checking for changes on the server, the server would send the data when a given event would happen?
What I'd like was the client not needing to send requests periodically but instead the server would only send the info to the client which in turn would have some kind of event listener.
Thanks in advance

Yes, this can be done. It is referred to as "push" or "push streaming".
Here is one website that offers the ability to do this: InstantPush. And a brief quote from their home page:
"InstantPush is used to make web pages
and mobile phones go live. They will
instantly be updated in real time when
a change occurs at the server side.
Standard web communication makes
updates pass firewalls and proxies.
Without any modules at the client
side!
InstantPush has been used since 2001,
before "Ajax was invented". It is
probably the First Ajax Push
Framework.
InstantPush is leading the market in
northern Europe."
Here is another company offering this technology: LightStreamer. And a quote from their home page:
"Lightstreamer is a scalable and reliable Server for pushing live data to Rich Internet Applications
Based on the Comet and Real-Time Web
paradigms, it streams real-time data
to any Web browser and client
application. HTML, HTML5, AJAX, Flex,
Silverlight, Java, .NET, iOS, Android,
and BlackBerry applications, can
easily receive live data from
Lightstreamer Server.
Lightstreamer has been used in many
mission-critical production systems,
where scalability, low network impact,
bandwidth management, adaptive
streaming, and other advanced
features, have proven fundamental."

This cannot be done because the http protocol works by sending a request and receiving a response from the server, hence the server cannot a response without receiving a request.

No this cannot be done. A server's job is to serve up results from a request, one that it must have to begin with.

That is not possible using traditional HTTP. You can, however, use long polling or one of its siblings to simulate push behaviour.

I think that websockets is the way to go, but is not supported for all browsers yet.
I used them with ruby and chrome and was pretty easy.

this is indeed a difficult ask where server broadcasts/pushes data to clients without being requested. HTTP is stateless and even if browser is a registered client, it still needs to request either through code or through some tags like meta refresh. New but still not so stable options are Comet or websockets.
Answer is Comet rather than websockets. YES, it is possible.
Another way is using Browser plugin.
This is an except from wiki page at Push Technology
* Apple Push Notification Service
* BOSH
* Comet
* Client–server model
* File transfer
* Pull technology
* Push Access Protocol
* Push e-mail
* Reverse Ajax
* Streaming media
* WebSockets

Possible to make HTTP request to a web browser?

This question is for my curiosity only:
Is it possible to make a HTTP request from a backend server to a web browser, that is to say I have a HTTP server ON the web browser to listen for incoming HTTP requests?
Cause I want to use frontend <-> couchdb directly thus dumping the backend server .. but then i wondered how i would do normal processing when the database javascript is not sufficient.
That thought made me think of this question.

Generally speaking — no.
There are some exceptions, Opera has a feature called "Unite" which allows it to run a web server (this is not turned on by default!) as well as acting as a user agent. That wouldn't allow you to send a response to a request that hadn't been made though.

Most web browsers don't have a web server and they are unable to accept HTTP requests. Maybe there is an extension for Firefox, but that's not a typical use case.
Depending on what you are trying to achieve, using Comet or long polling could work for you.

Can I receive a stream over HTTP with JavaScript, Flash, or Silverlight?

I'm prototyping a realtime notification mechanism using http over port 80. The aim of the project is to allow a Flash application to respond to an event on a remote server quickly (specifically an inbound phone call being connected to a phone next to the computer.) Polling is one approach, but is too slow. Currently I use a socket connection to get low latency notification of the events on the server, which works well but isn't firewall friendly. I don't want to install anything except Flash, or Silverlight on the client. Cross compatibility of browsers isn't a concern - in this application I can specify what browser the client uses but IE is preferred.
I've made a server HttpHandler in .NET which never closes the connection and sends the "events" to the client by writing out bytes to the http response stream (ConnectedClientContext.Response.OutputStream.Write etc) and I have a .NET client application which can read these messages okay.
My Question:
Can I receive the bytes from the server over HTTP as they arrive using JavaScript, Flash or Silverlight? So far I can only find a way to get notified of the "download progress" and don't get the actual bytes until the response is closed - I want them as they arrive.
Best Regards,
Daniel

I don't know about Flash but in Javascript (by which you mean in browser) and Silverlight you are limited pretty much to the http protocol.
You can use the AJAX Http Streaming pattern. The basic ideas which is different from what you are trying is that as soon as data is available outstanding request ends and a new is immediately initiated asychronously, mean while your client process the newly arrived data.
Silverlight gives you more options since is HTTP stack is purely asynchronous but you can get your hands on the stream to you as soon as data starts to arive by setting the HttpWebRequest.AllowReadStreamBuffering to false. (Unlike XmlHttpRequest which always buffers).

it's very easy to use the Comet ideas for notifications. you don't even have to use a comet-specific framework. simply do an ajax request with a callback on answer, wrap this on a loop and you have an event loop, just like a GUI app. on the server side, don't bother answering the request until there's either an event, or a timeout (which is just a 'null' event).

Flex and Flash have several AMF/XML remoting libraries available that support data pushing. I would certainly look into that.
http://raghuonflex.wordpress.com/2008/04/17/data-push-in-flex-with-backend/
These libraries use a Comet - like implementation to achieve this.