OT: Live Support Chat script/solution?

[Matthias Rebbe]

Hi,

does anyone know if there is a free LiveChat/LiveSupport tool available.I am looking for a solution where my website visitors can press a link on my site and a chat windows opens where they can contact me online by chat.

I had something already, but the chat app for me was a windows program. But i am looking either for an mac app or better a solution where i have also to login from web instead from a desktop application.
 I am looking for a solution i can host on my server. Searched Google already, but found only commercial ones with a monthly fee.

Regards,

Matthias