Microsoft announced today that it will be releasing a Tech Preview of what they're calling Azure Stack. While Microsoft has had some success with their public cloud, Azure, they're banking on companies not actually going full public cloud, whether that's due to security, cost, or skillset. Microsoft isn't the only company offering a hybrid cloud solultion, but it's the only one I know of that will be totally consistent across the on-prem and off-prem data centers.
While some are saying this will help differentiate themselves from AWS and Google, who are also leaders in the public cloud market...it looks to me like they're actually targeting VMware and OpenStack. I mean, it's even called Azure Stack. OpenStack is an open source project that is used by companies like RackSpace in the public cloud sector. However, even VMware and OpenStack can't claim to have total consistency between sites. While I haven't tried it, it's also possible it could be less complicated than deploying OpenStack since it's not open source.