TeamSpeak Classic
TeamSpeak Classic - also known as TeamSpeak 1.5 - was first released in October of 2001 and set the foundation to the TeamSpeak legacy.

Released as "Freeware", the first version of TeamSpeak featured a client-server architecture, firewall-friendly client communication, multiple channels (formerly known as "rooms"), user administration, and cross-platform support for both Windows and Linux. At the time, TeamSpeak Classic's competitors lacked either most or all of of these features and were not nearly as scalable of a solution.

Today, the TeamSpeak Classic product is now "retired" and is no longer supported.