Starting from Mosets Tree 2.1 and Hot Property 1.0, both extensions are released under GNU GPL license. You can find the full text of the license here:
This means that you can install Mosets Tree 2.1 and Hot Property 1.0 on any number of websites.
Please note that our support is based on per site subscription. Which means when you purchase a site subscription, you are entitled to register a single site in which we will provide support for. If you wish to have support for 2 or more sites, you will need to purchase additional site subscription. You can find more about the pricing at the following pages:
Mosets Tree - http://www.mosets.com/tree/pricing/
Hot Property - http://mosets.com/hotproperty/pricing/