Me and my body coded a messenger for our site like a year ago. And we dont use it anyway. He is the master coder and I still have the codes here. Maybe someone could give a try to integrate this with vbulletin so we can all use.
I will add the code here as a zip file. The main problem the language we used is Turkish

So if anyone want to work on this please contact me so I can help you with the language.
You can Pm me.
I have no problem about the license or something else. If anyone want to give a try he can release it under his own name. I just want to have a working messenger for my board