Apprenda is attempting to fill the gap left by Microsoft Azure for an on-premise .NET PaaS. It supports .NET, SQL Server, ASP.NET & Silverlight. In November the company added new features that make it easier to run existing .NET code on Apprenda servers, speeding up migration to the PaaS. This will likely remain its competitive selling point against Cloud Foundry and Microsoft (in the event of an on-premise Azure).
The benefit of running a PaaS on-premise is the ability to quickly provision servers with elastic resource use while keeping them running in a private data center. A company could also deploy a PaaS system to a public infrastructure-as-a-service cloud to gain better control and customization of their PaaS, or to make migrations between providers easier.
(Original Article: September 20, 2012 by Maria Deutscher, updated January 11, 2013 by Klint Finley)