Microsoft's answer is a little less ambitious, too.
Rather than offering the base code for its Azure PaaS cloud as an open-source standalone offering, it offered more granular contracts and pricing for Azure in an effort to draw in open-source developers who might otherwise run their apps on Amazon's EC2 or Google.
Its "open" focus was on making it easier for content partners to get stuff up on Azure, not make the code or platform itself more open.
It did issue a new version of the Azure SDK that makes it easier to port apps through IIS to Azure; it also issued an early beta for a Traffic Manager that acts as a performance manager for apps running on Azure.
And it promoted Orchard 1.1, the open-source content management system from the OuterCurve Foundation, whose code works with Azure's Microsoft-centric cloud because Microsoft helped found and promote it.