When Microsoft acquired InRelease, later Release Management for Visual Studio in 2013 you had to pay a license for each agent deployed on every server you wanted to deploy to. Even though you got licenses together with Visual Studio Ultimate these agents would cost a lot of money for big companies.
Effective January 1, 2015, target servers receiving automated deployment from Release Management Server will no longer require a Visual Studio Deployment license, in other words, it’s free!
From the licensing whitepapers:
To utilize the Release Management solution in Visual Studio 2013, you must acquire licenses for the following:
- Each person using the Release Management Client for Visual Studio 2013 for creating, updating or deleting a release pipeline sequence must be licensed for either Visual Studio Ultimate with MSDN, Visual Studio Premium with MSDN, Visual Studio Test Professional with MSDN or MSDN Platforms.
- A Team Foundation Server CAL is not required to approve stages or sign off on a release.
Read more about in in the Visual Studio and MSDN Licensing White Paper