Azure App Service with Logic Apps and Connectors are a new offering that directly impact BizTalk in Azure. Currently, Azure App Service is in Preview and its features are still in development. As a result, Logic Apps are purposely not added to this topic.
When Logic Apps are no longer in Preview, it will be added.
Get Started with Logic Apps.
BizTalk Server 2013
BizTalk Server 2013 R2
BizTalk Server 2013 R2:
BizTalk Server 2013:
The operating systems are the same as BizTalk Server on-premises. The virtual machines in the Gallery automatically include the operating system.
If you purchase an on-premises BizTalk Server 2013 or 2013 R2 license, you can install BizTalk Server on a Windows Azure virtual machine. The BizTalk Server license includes installing on-premises and installing on a Windows Azure virtual machine.
Client computers: Limited to operating systems supported by the Microsoft Azure BizTalk Services SDK:
Installing Azure BizTalk Services SDK
BizTalk Service: Completely managed by Microsoft and hosted on Azure. Users focus on the application needs.