Which language is good for IM

Answer 1

Since most Instant Messaging is done over the internet you should try HTML and javascript.
HTML will help you create the form and Javascript will add the functionality

Answer 2

Codeacademy.com has a good tutorial on how to create a messaging service like Twitter. It is not exactly what you're asking but is very close

Answer 3

thanks a lot

Answer 4

Depends if you want to make a game or a website