Ventrilo

Probably the most popular VOIP application out today among gaming Clans, due to it’s superior voice quality and multitude of features. Current version is 3.0.

Ventrilo Interface

Pros

• Sound Quality is second to none due to the Speex Codec (GSM is also available).
• Easy to use interface.
• Client supports both PC and Mac.
• Text to Talk feature. If you can type it, Ventrilo can say it.

Cons

• Text to Talk feature. Some find it annoying and turn it off.
• No Linux Client Support.
• Admin Interface is not web based like TeamSpeak’s.
• If you wish to host a server with more than 8 connections, you’ll need to rent a server from a hosting provider.

You can download Ventrilo from their website.

A wide range of companies host professional Ventrilo servers on server grade hardware, ensuring that your server is always available. My personal favorite is GameServers.

TeamSpeak

Without a doubt the most scalable solution. TeamSpeak can host hundreds (if not thousands) of users simultaneously. Most notable of TeamSpeak’s features is it’s Web based Admin interface and loads of options and permissions. Current Stable Version: 2.0

TeamSpeak 2 Interface

Pros

• Access the Admin interface via your web browser from anywhere in the world.
• Tons of permission settings and options.
• Extremely scalable thanks to a built-in SQLite Database.
• PC and Linux Clients available.

Cons

• Sound Quality is not quite as good as Ventrilo.
• No Text to Speech Capabilities (Some might consider this a Pro).
• Slow development speed. TeamSpeak 3.0 has been in development for several years.

You can download TeamSpeak from their website here.