1.Eucalyptus:

Eucalyptus is a Linux-based software architecture that implements scalable private and hybrid clouds within your existing
IT infrastructure. Eucalyptus allows you to use your own collections of resources (hardware, storage, and network) using
a self-service interface on an as-needed basis

You deploy a Eucalyptus cloud across your enterprise’s on-premise data center. Users access Eucalyptus over your
enterprise's intranet. This allows sensitive data to remain secure from external intrusion behind the enterprise firewall.
You can install Eucalyptus on the following Linux distributions:
• CentOS 6
• Red Hat Enterprise Linux 6