VSTunnel (Mac/Win; $85) is a VST and Audio Units plug-in that lets you connect several sequencers over the Internet. It is used as an insert effect in the sequencer's master out channel.
You can start a session, or join a session that is already in progress. When you create your own session, you decide whether to make it public or private. In a private session, no one can enter without knowing the session key, and as the session creator, you have the power to choose your session members.
A list of all public sessions is offered to the user, and it can be sorted by genre. During a session the music played is analyzed by VSTunnel: Local changes are recognized, compressed, and transmitted to the other session participants.
According the company, all Mac/Win sequencers that host VST or AU plug-ins are supported. You can download VSTunnel for free. In the free version, all saving functions are disabled, the maximum song length is limited to one minute, and the download quality cannot be adjusted. When you pay for your registration code, all of the features become available. For more information, click here.