We are starting public alpha test of our multiplayer game matchmaking system - https://gamz.tv.
Soon we will publish our games there. Also you can integrate with us - it's free, no SDK required.
How it works? Your daemon process can connect to GamzTV cluster and receive requests coming from messengers. As a response you can show form with controls that can generate postback, open your page in browser (for example to download your game) or launch your executable (if your game already installed and provided special launch reference). Also you can attach already implemented chat control to your forms to easily make game lobby.