OpenStack is a collection of open source software projects that enterprises/service providers can use to setup and run their cloud compute and storage infrastructure. Rackspace and NASA are the key initial contributors to the stack. Rackspace contributed their “Cloud Files” platform (code) to power the Object Storage part of the OpenStack, while NASA contributed their “Nebula” platform (code) to power the Compute part.

OpenStack Components

• Compute Infrastructure (Nova)
• Storage Infrastructure (Swift)
• Imaging Service (Glance)

More on this @ http://docs.openstack.org/diablo/openstack-compute/starter/content/OpenStack-d1e94.html

Why OpenStack?

Control and Flexibility
Open sourceplatform means you’re never locked to aproprietary vendor, and modular design canintegrate with legacy or third-partytechnologies to meet your business needs.

Scalability.
With massively scalable publicclouds in the petabyte storage range,OpenStack is already running in globalcorporations providing secure public andprivate cloud infrastructure.

Open Industry Standard
More than 75leading companies from over a dozencountries are participating in OpenStack,including Cisco, Citrix, Dell, Intel andMicrosoft, and new OpenStack clouds arecoming online across the globe.

Openness and Compatibility
Avoidproprietary vendor lock-in with Apachelicensed source code delivering compatibility with thousands of existing public andprivate clouds for seamless transition fromcloud to cloud.

Flexible Technology
Global ecosystem of industry leading vendors supply integrationsupport for a wide variety of features withinthe cloud. As an example, hypervisorsupport includes ESX, Hyper-V, KVM

OpenStack Overview Datasheet