OpenSimWorld is the directory of 3D Virtual Worlds based on OpenSimulator and connected through the HyperGrid. Learn More

What to do if you missed out on vivox voice? Well. There is a free program for windows/linux/mac called mumble. It has 2 parts. a program that you run as a small server, and a program that you run as a client. Mumble currently supports over 30 games, including such games as call of duty with an overlay plugin. An overlay plugin is not yet developed for opensimulator, however... Here are the instructions to do that if you want a game overlay plugin for opensimulator.
BUT you don't have to do all that. You can just run the mumble server, then you and your friends can download the mumble client on their mac, linux box, or windows pc, and they can easily connect to your mumble server. Once everyone is on your mumble server they can type chat to each other, or talk voice to each other over their microphone. The game overlay part just adds additional features to the game, so that it appears your voice is coming from a specific location, rather than being ubiquitous. If you have any questions on how to set up your own private voice server, please msg me, and I will help you. :)