Cloud Computing is computing resources and access platforms which are stored, hosted and carried out in a foreign (3rd party) data server configuration.
With Cloud Computing, companies can scale up to massive capacities in an instant without having to invest in new infrastructure, train new personnel, or license new software. Cloud computing is of particular benefit to small and medium-sized businesses who wish to completely outsource their data-center infrastructure, or large companies who wish to get peak load capacity without incurring the higher cost of building larger data centers internally. In both instances, service consumers use what they need on the Internet and pay only for what they use.
The service consumer no longer has to be at a PC, use an application from the PC, or purchase a specific version that's configured for smartphones, PDAs, and other devices. The consumer does not own the infrastructure, software, or platform in the cloud. He has lower upfront costs, capital expenses, and operating expenses. He does not care about how servers and networks are maintained in the cloud. The consumer can access multiple servers anywhere on the globe without knowing which ones and where they are located. 
Cluster computing is one subset of Cloud Computing.
Grid computing is another.
Virtualization is a core component of Cloud Computing which divides the available resources on a given hardware and/or software configuration into specific representations for specific users, organizations or communities.
- Ubuntu Cloud Computing: http://www.ubuntu.com/products/whatisubuntu/serveredition/cloud
- Ubuntu Cloud Planet: http://cloud.ubuntu.com/
- Ubuntu cloud-computing components released : http://news.zdnet.co.uk/software/0,1000000121,39644425,00.htm
Eucalyptus is an open-source system for implementing on-premise private and hybrid clouds using the hardware and software infrastructure that is in place, without modification. Eucalyptus adds capabilities such as end-user customization, self-service provisioning, and legacy application support to data center virtualization features, making IT customer service easier, more fully featured, and less expensive. Eucalyptus can be downloaded for free and used forever. It includes Amazon Web Services API (EC2, S3, EBS) and support for Xen and KVM, and allows you to build a cloud in 6 steps.
The Eucalyptus slogan is:
Your Hardware. Your Data. Your Cloud.
- Eucalyptus: http://www.eucalyptus.com/
Unified Cloud Interface
Unified Cloud Computing is an attempt to create an open and standardized cloud interface for the unification of various cloud api's. A singular programmatic point of contact that can encompass the entire infrastructure stack as well as emerging cloud centric technologies all through a unified interface. One of the key drivers of the unified cloud interface is to create an api about other api's. A singular programmatic point of contact that can encompass the entire infrastructure stack as well as emerging cloud centric technologies all through a unified interface.
In this vision for a unified cloud interface the use of the resource description framework (RDF) is an ideal method to describe a semantic cloud data model (taxonomy & ontology). The benefit to an RDF based ontology languages is they act as general method for the conceptual description or modeling of information that is implemented by web resources. These web resources could just as easily be "cloud resources" or API's. This approach may also allow us to easily take an RDF -based cloud data model and use it within other ontology languages or web services making it both platform and vendor agnostic. Using this approach we're not so much defining how, but instead describing what.
- unifiedcloud -- Unified Cloud Interface (UCI): http://code.google.com/p/unifiedcloud/
- Shuttleworth - standards and open source against 'gross' cloud lock-in: http://www.theregister.co.uk/2009/04/01/shuttleworth_cloud_standards/
- Cloud Myths Dispelled: http://www.eucalyptus.com/enterprise/info/cloud-myths-dispelled/
- Is cloud computing more than just smoke?:
- Is Amazon the Wal-Mart of Cloud Computing?: http://www.appistry.com/blogs/sam/amazon-wal-mart-cloud-computing
- A Break in the Cloud? The Reality of Cloud Computing: http://www.cluteinstitute.com/Programs/Prague_2009/Article%20439.pdf
- April's Fools DAY -- YouTube Flails, Amazon Cloud Computing In A Blimp, 3D Chrome Browsing, Google Masters A.I.: http://www.charged.co.za/latest-news/april-fools-youtube-flails-amazon-cloud-computing-in-a-blimp-3d-chrome-browsing-google-masters-ai
- CODING HORROR -- Scaling Up vs. Scaling Out -- Hidden Costs: http://www.codinghorror.com/blog/archives/001279.html
- Markus at PlentyOfFish -- Upgrades, Themes & Date Night: http://plentyoffish.wordpress.com/2009/06/14/upgrades-themes-date-night/
- Jonathan Koomey -- The Environmental Cost Of Cloud Computing: http://www.slideshare.net/gigaom/jonathan-koomey-the-environmental-cost-of-cloud-computing
- Cloud computing is for the birds: http://money.cnn.com/2009/05/04/smallbusiness/cloud_computing_is_for_the_birds.smb/index.htm
- Hooking Stuff Together - Programming the Cloud: http://www.infoq.com/presentations/programming-cloud-gregor-hohpe
- Cloud .vs. Grid: http://www.ibm.com/developerworks/web/library/wa-cloudgrid/index.html?ca=drs-
- Ubuntu promises DIY Amazon cloud: http://www.theregister.co.uk/2009/03/25/ubuntu_amazon_cloud/
- Why Microsoft should fear Ubuntu’s cloud efforts: http://www.ubuntu-news.net/2009/02/23/why-microsoft-should-fear-ubuntus-cloud-efforts/