The ideal solution would be multipronged: 1. All the code is open source; you can host on your own servers if you want. 2. If you want to host on your own ser

The ideal solution would be multipronged: 1. All the code is open source; you can host on your own servers if you want. 2. If you want to host on your own servers and you're a commercial outfit, you probably want a support contract. 3. If you don't want to be bothered with that and you don't mind about the NSA, you can use it as a cloud service on our servers with a minimal version for free and a commercial version for a subscription fee.