This is not really the right place to post this, but I could not find a better section. I want to create my own Instant Messenger, like AIM, but much simpler, with less features. I am sure however this is done it is incredibly difficult, but still I would like to give it a shot. How is this done? What language is used to write it?

p.s - Not a web one, an actual instant messenger such as AIM.

I've never even tried something like this but here are a few tips (may be useless ones, though!)

The first thing to look at is how the instant messenger is going to run. There are two different methods. First is the 'ICQ method', where you login through a server and get the IP addresses of all the contact list members. Then, messages etc. are sent directly to the IP address.

The other method is the MSN method, where all messages are routed through the central server. It is really up to you which method to use.

I would recommend using C++ Builder or Delphi to create the actual messenger program. These come with good web interaction which will be vital. They are also visual programming tools which will make creating the GUI better.

On the server you will need some sort of database (MySQL perhaps) and a web server (Apache would be my choice). Then its really all up to you!

I suppose it would work something like this:
1. Client sends logon details to server
2. Server gets client's IP, logs them in to the server, and sends confirmation to a pre-specified port on which the client is listening
3. User's contact list is loaded and data sent to client with details of who is online etc.
4. Server notifies all users who have the client on their list that the client is online

Then to send a message:
1. Client sends message and username to server
2. Server looks up IP of username and sends message to their 'listen' port

Also you would need to send a message from the server to the client regularly and, if it was not replied to by the client software, log them off.

Hope that rambling is of some help

<edit>
You may also want to have a look at some of the projects on SourceForge. There are a cople of messengers (like Miranda (I think)), which might be helpful to you. ICQ also used to provide an API, which you could download and look at.

Another useful thing to look at would be AOL's interoperability document, which described a lot about how AIM works. If you can't find a copy online, let me know as I think I still have one.

I don't know too much about this but I would warn about the security risks. Aol,Msn, and icq spend tons of money on building the security so that IM's cannot be used to execute a 'multi-hack' type operation. I realize that this is only for you to fool around with but I would not post it on the web or distribute it in any way until you think of security. Anyways you got a long way to go so good luck. I have some c++ experience so PM if you have some q's about c++. Good luck.
-dk

Odd coincidence. Less than a minute before reading this thread I was thinking about making an IM myself. Add to that the fact that I only accidentally came to this page (hit the wrong bookmark).

Anyway, if you are able to use Visual Basic, you'll find it's simple enough to slap on a Winsock control and a few lines of code to make a crude IM app. Check out this tutorial by Karl Moore for more: http://www.developer.com/net/vb/article.php/1540141

It is also possible to create your own interface with VB that uses, say, the MSN Messenger framework to communicate. I don't have any links ATM, but I do remember reading a tutorial on it (possibly at the same site linked to above). I'll have a mosey 'round and post back anything I find.

How to make your own MSN Messenger In VB

Hi Mo Money,

Actually, while I was taking my Java course this summer, I saw that there was this one guy who created his own IM in Java. It was very simple, and I am sure that it could have been very easily exploited. But it only took 5 days. I hope that gives you a bit of hope.

However, it certainly wasn't basic code, and the person was obviously very familiar with Java. I recommend that you make yourself very familiar with either Java, C++, or VB before you approach this massive project. But keep in mind dk01's warning - it'll be hard to create a secure program.