A family of Microsoft server products that support large-scale implementation management of enterprise application integration processes.
I found this information in this FAQ here that you may find useful:
How do I license BizTalk Server in Azure Virtual Machines?
- If you are an end-customer using BizTalk Server, you can:
Obtain a BizTalk Server image from the Azure Virtual Machine marketplace and pay the per-minute rate of BizTalk Server, or
Install or upload your own BizTalk Server image using the license mobility benefits under Software Assurance. - If you are a Service Provider with a signed Services Provider License Agreement (SPLA) you can:
Obtain a BizTalk Server image from the Azure Virtual Machine marketplace and pay the per-minute rate of BizTalk Server.