Are there any chat clients or stand-alone clients that can interact with the iMessage server? I just switched from OSX 10.8.x to Ubuntu 12.10, and it's really the only thing I miss.
This message is quoted from https://apple.stackexchange.com/a/66047:
iMessage is based on a propietary, binary and encrypted protocol (source Wikipedia) with a client side device certificate, which makes it unlikely to be reverse engineered and implemented in third party apps any time soon (although attempts are being made).
Edit
It may be possible in the future to run the native OS X applications on a Linux OS similar to how we can run Windows applications using wine's compatibility layers. The Darling Project aims to do that. However, I have never encountered a situation where I needed to run a native mac application, so I have never tested it. This does seem promising, though somewhat doubtful. The following is quoted from wikipedia:
Just like APNS it sets up a Keep-Alive connection with the Apple servers. Every connection has its own unique code, which acts as an identifier for the route that should be used to send a message to a specific device. The connection is encrypted with TLS using a client side certificate, that is requested by the device on the activation of iMessage.
