In Zigbee terminology, the central point of intelligence in the network will often be a Combined Interface Device. You can view a list of certified CID's here. Aside from this list, many of the leading Home Automation and Building Automation platform vendors support Zigbee. For example:

• Samsung SmartThings
• Icontrol Networks
• Daintree ControlScope
• Iris by Lowe's
• Wink
• Control4
• Crestron

Keep in mind that each one of these vendors has their own certification process and some custom features may be required for full compatibility with their systems. In other words, the first step in deploying a product to these systems is to contact the platform vendor and ask for their requirements specifications.