The user fills the field on the site and clicks to send, the information is immediately sent to the operator’s messenger (without a difference, what a messenger or qip, or miranda, etc.).
In what language can I organize sending from the server to the messenger? Is it possible to do this on PHP, do you need any libraries for this?
I do something similar to Krible.ru and Livetex.ru (services providing online Consultation on the site).
If under the messenger you understand the XMPP client, then for PHP there is a xmpphp , which is intended for sending messages via XMPP server.
For ICQ there is a class webicqpro