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jQuery alternatives for multiplayer games?

First off, I am not asking for any code or anything like that.
all I need is some advise.
I'm creating a roulette game and everything in my roulette game is based on jQuery.
however, as we all know, jQuery is client side so I was thinking about using AJAX to send some details back to server and from the server to the users browser so I can make this roulette game work in "multiplayer" fashion... But the issue is that I don't think its possible to send the roulette's wheel animation to the server and back to users browser so I am a bit confused about this!
In my research I came across some information (old ones) about using node.js and jquery together! I don't know if this is possible or how easy it would be to use my jquery code in node.js as I have never used node.js before..
so the question that i have is:
based on the information i provided above and my requirements, what are my options?
can I use AJAX to achieve what i am trying to do and if so, a bit
information would be great.
if AJAX is out of question, is it possible to use my jquery code in
node.js to achieve what I am trying to do?
ANY ADVISE WOULD BE APPRECIATED.
P.S. I don't want to use HTML5 as 1st I don't know much about HTML5 and also, some devices, browsers do not support it.
Thanks

The best way is to use websockets to ensure real time communication. One of the best alternatives for implementing that could be using a server under node.js. Have a look to this video from Code School node.js tutorials: https://www.youtube.com/watch?v=mtDK4jf4RS0 where is ilustrated how to implement a real time chat. Your problem is based on the same.

There are three parts to a multiplayer game displayed in a browser:
client-side display,
server-side data management,
client-server communication.
If you're already set on your display technology (jQuery), then you're probably going to use $.ajax() for client-server communication. However, technologies used for server-side data management are completely up to you and they don't necessarily have any connection to the technologies used for display and communication (meaning the traditional communication initiated by client).
Basically, use any kind of server technology stack you like. Node.js might do just fine but there are many other viable alternatives. They just need to support communication with the client.
So, to be absolutely clear, your question doesn't really make sense. You might use jQuery in the client and Node.js on the server, but they will never really "work together". They will manage completely separate parts of your application and connect through protocols not specific to either of them.
As for the animation, the animation itself is solely a client-side problem. If you want to "synchronize the animation" across multiple clients, you can let the clients communicate with the server, but they only ever need to send/receive plain data. Then you adjust the client-side animation based on the received data.
As another poster points out, websockets are a better fit for this than regular client-initiated HTTP requests. Not because of "the animation", but because you want all the clients to receive the information about the start of betting at the same time.

I am also developing a MMO game using javascript only. Firstly, there are two different types of javascript here. Usual client side javascript (the one you already know) and the server side javascript (i.e. Node.js).
You will need to develop both client and server before connecting them with jQuery's Ajax. So you need to study Node.js before designing overall architecture of your game.
I read many Node.js tutorials and watched many youtube tutorial videos but I was still confused, before I really sat down and read a good textbook that explained from basics, one like below. Try to get hold of it from your local library.
Express web application development learn how to develop web applications with the Express framework from scratch by Hage Yaapa
Express is the popular framework that runs on Node.js now. So it's worth getting familiar with Express Framework. Once you understand how express app works (not so difficult), you will see how you can frame your game structure like I did :)
In order for many clients to share same animation, there must a server that synchronizes the game state. Ajax can only link between server-client communication in my understanding. There is no mechanism that connects between clients. The clients ask server what number was the result of roulette roll and show the corresponding animations.

Yes, you can use NodeJS and jQuery together.
NodeJS is server-side, meaning that you set up a server (a lot of people use the Express module, which is easy to use), which serves content to clients asking for it. Your server-side code can be in any language supporting sockets, not just NodeJS. But NodeJS is easy to use if you know JS already.
jQuery is client-side, meaning that it's executed by the user's browser, and may or may not have a server-side component (if it doesn't need it), or it might have one where it sends requests to the server-side code. When it requests a page from the server, it can be static content (like when you request index.html) or dynamic via an AJAX request. Client-side browser code must be HTML/CSS/JS (you can't make Firefox or Chrome interpret C, for example).

Connect server hosted webapp to local websocket

Has anyone an idea for the following scenario?
I have a RIA-Webapplication (realized in ExtJs). What I want to implement is the possibility to use local ressources like card readers or fingerprint readers or other serial devices and filesystem access.
I thought about implementing this with a local websocket service which has to be installed by our customer before using our RIA the first time. When the webapp is loading it should scan the local machine if a websocket service is available and connect to it.
After that, local events (like new card is beeing read or recognized new finger) should be passed to the browser via websocket connection.
Any ideas how to get started with such a solution?

I have made something like that. Besides the obvious things such as read/write/poll data from the card-readers and so on, you would have to either implement everything yourself or, use a library for technology you are going to employ for your web-server. So, if you use a LAMP solution, i think there are some web-socket libraries for PHP that you can use. However, if you do everything by yourself then you have to implement everything from hand-shaking, to creating data packets. I have done everything from scratch by using .NET and it provides a number of useful libraries such as hashing. Java also would be a good option and have those kind of libraries as well. In general if you doing everything by yourself i would say the trickiest thing would be to split the data you want to transmit among various data packet. It is not that hard to do things from scratch. The RFC (https://www.rfc-editor.org/rfc/rfc6455) helped me a lot. Hopefully, this helps.

GWT server with get() and post() built on client end

This is more of a curiosity really, to see if some one has done anything similar, or if at all it is possible.
I'm working on a project that will get notification through external notifications. Now I could go about doing this by having notifications coming to my server and have a comet setup between my client and server.
BUT
I was wondering if I could write server logic into my client and listen out for notifications from external sources. Immediately one issue I see is, external sources would need callback URL etc, which I dont know if you could do from client side (unless one could use the IP address in that way).
As you can see it is more ideas and discussions if such a thing was possible, this is somewhat inspired by P2P models whereby you wouldn't be mediating things through your central server.
Thanks in advance!

GWT compiles (nearly) Java source into JavaScript, so compiled GWT apps can't do anything that traditional JavaScript running in the browser cannot do. The major advantage of bringing Java into the picture isn't automatic access to any/all JVM classes, but the ability to not only maintain Java sources, which tend to be easier to refactor and test as well as keep consistent with the server, and to compile that statically defined code into JavaScript, performing all kinds of optimizations at compile time that aren't possible for normal JavaScript.
So no, while you can have some code shared by the client (in a browser) and the server (running in a JVM), you can't run Tomcat/Jetty/etc in the browser just by using GWT to compile the java code into JS.
As you point out, even if this was possible, it would be difficult to get different clients to talk back and forth, without also requiring that the browsers can see and connect at will to one another. BitTorrent and Skype have different ways for facilitating this, and currently browsers do not allow anything like this - they are designed to make connections to other servers, not to allow connections to be made to them.
Push notifications from the web server to the browser are probably the best way forward, either through wrapping comet or the like, or through an existing GWT library like Atmosphere (see https://github.com/Atmosphere/atmosphere/tree/master/samples/gwt-demo for a demo).

Creating a fully functional website while only using vanilla coding

When I say "Vanilla Coding", I am referring to websites that don't utilize server side coding (such as PHP, ASP, etc.), only HTML, JavaScript, and CSS.
I know that there are a plethora of sites that already exist that don't utilize (to my knowledge) any of the common, server side languages used by many others (PHP, ASP, etc.), but still function just fine!
I am confused! How do these sites continue to save login information, keep records, etc. etc. without using a server side scripting language? Is there something that I am missing? Can JavaScript access more (such as databases and local files) than what I thought it could?
EDIT
Turns out I've made a serious and shameful mistake in assuming that just because it ended with a .html extension that it was client-side only. That is okay though because I'm learning. Thanks so much for the help everybody!

Essentially, unless you have some sort of server-side programming, you don't stand a chance at making a site with any amount of functionality. To break it down for you:
What you can do without server-side scripting:
Serve static pages
What you need server-side scripting for:
Absolutely everything else
Even something so simple as keeping a site consistent and up to date is a nightmare on wheels without, at the very least, some some sort of management system that pre-generates the static pages to be served. (Technically, one could argue that Copy+Paste in Notepad counts as this.)
As has been mentioned elsewhere; obfuscating the true nature of precisely what system is being used is trivial; and having URLs ending in, say, .html while using PHP is no issue.
Edit: In the most perverse case I can think of off the top of my head, you could have a lighttpd server masquerading as an IIS server, serving pages generated by an offline renderer fed to it by a Perl FastCGI script, sent together with PHP signature heading and using a mix of .asp and .jsp file extensions.
Of course, noone would do something as silly as that. I think…

No client side script can access server side information (like a database) without some sort of server side communication (through something like ajax or the like)
If you really ( i mean really as in don't do it ) want to do logins and the like on clients side, you would have to make some sort of cookie that you store on the user's computer, also you would need a list of users (which anyone can read) to use against

This answer is very late but I leave this reply for anyone who may stumble upon it.
Using javascript/jQuery, and various APIs a simple site can be created only using client-side coding.
For instance, a simple shopping cart type of site can be created. I've done it before.
There are few (not many) strictly 100% jQuery based shopping cart solutions that are open-source.
How does the PG (pay gateway) get taken care of? You are limited to accepting payment through paypal, google checkout, and direct deposit.
What about allowing customers to leave comment? You can use API's like Disqus. What about chat support? Zopim is pretty handy.
How do you get notified when purchase is made? Paypal & google checkout notifies you.
What about sending mass email? Mail Chimp.
Personally, I almost always use WordPress or some other types of CMS but using only vanilla coding to build a simple site is not only feasible but very sensible in certain circumstances.

You're not going to see whether a site is using a server side language unless they let you see the file extensions. With URL rewriting, MVC patterns, etc., it's easy to hide, or even fake that information. Therefore, chances are very good that the sites that you think aren't using a server side language are actually using one.
Now, a site can save certain information in cookies, such as some basic preferences, but any authentication they appear to be doing wouldn't actually be doing anything without a server-side script accessing a database somewhere.
As a side note - I have worked on a site where the content was actually static, but made to look like a blog or CMS. It was an absolute nightmare and hugely error-prone.
What are these sites that you think aren't using server-side scripting?

Nowadays a lot of sites are using Javascript as a server side solution, Node.js being the most popular. Check out this list: https://github.com/joyent/node/wiki/Projects,-Applications,-and-Companies-Using-Node

Connecting to remote hosts in an HTML/Javascript web app

I've been thinking of developing a web application using HTML and JavaScript for a little while now, but I've hit a wall during my ponderings. I want to be able to connect (long-term, not briefly) to a remote host with this app, one which is unfortunately not the server that the page was requested from.
From what I've read, JavaScript can't support long-term connections, and furthermore it won't request from anywhere that's not the domain the page was downloaded from. I considered hidden Java or Flash objects, but Flash seems to cost money, and Java requires a signed applet (and I don't know whether it's worth getting it signed).
The only solution that I think could work is using my server as a proxy to the others (through an unsigned Java applet?), but I really don't want to do that if I can help it. Is that my only realistic option, or are there other solutions I haven't considered yet?
(I considered asking on one of the other SO-alike sites, but StackOverflow seemed most apt, since this is largely a programming and design issue.)

After carefully considering my own plans for the application, I've decided to go forward with the server-as-proxy approach. Having the client handle the connections sounded like a good idea at first, to save on server resources, but it would have made other implementation ideas unworkable. Sticking to a strict server-as-proxy model handily solves these and other issues I was pondering over, so I suppose that's that!