Cyber movies

Preamble
Cloud computing is an approach to a shared IT infrastructure in which large pools of computer systems are linked together to provide IT services. Since it accesses "virtual" resources, cloud computing is not limited by the power and capabilities of local or remote computers. It is the next generation of enterprise data centers, which operate like the Internet, providing extreme scale and fast access to networked users. Cloud computing offers a simplified, centralized platform for use when needed, lowering costs and energy use. Unlike grid computing, which distributes IT for a specific task, cloud computing is used across an entire range of activities. The platforms getting the most media attention are externally hosted services, but others are used inside companies, especially those operating globally.
Introduction
Cloud computing is a style of computing in which dynamically scalable and often virtualized resources are provided as a service over the Internet. Users need not have knowledge of, expertise in, or control over the technology infrastructure in the "cloud" that supports them.
The concept generally incorporates combinations of the following:
• infrastructure as a service (IaaS)
• platform as a service (PaaS)
• software as a service (SaaS)
• Other recent technologies that rely on the Internet to satisfy the computing needs of users. Cloud computing services often provide common business applications online that are accessed from a web browser, while the software and data are stored on the servers.
The term cloud is used as a metaphor for the Internet, based on how the Internet is depicted in computer network diagrams and is an abstraction for the complex infrastructure it conceals. The first academic use of this term appears to be by Prof. Ramnath K. Chellappa (currently at Goizueta Business School, Emory University) who originally defined it as a computing paradigm where the boundaries of computing will be determined by economic rationale rather than technical limits.

Comparisons
Cloud computing can be confused with:

1. Grid computing - "a form of distributed computing whereby a 'super and virtual computer' is composed of a cluster of networked, loosely coupled computers, acting in concert to perform very large tasks".
2. Utility computing - the "packaging of computing resources, such as computation and storage, as a metered service similar to a traditional public utility such as electricity" and
3. Autonomic computing - "computer systems capable of self-management".
Indeed, many cloud computing deployments as of 2009 depend on grids, have autonomic characteristics, and bill like utilities-but cloud computing tends to expand what is provided by grids and utilities. Some successful cloud architectures have little or no centralized infrastructure or billing systems whatsoever, including peer-to-peer networks such as BitTorrent and Skype, and volunteer computing such as SETI@home.
Furthermore, many analysts are keen to stress the evolutionary, incremental pathway between grid technology and cloud computing, tracing roots back to Application Service Providers (ASPs) in the 1990s and the parallels to SaaS, often referred to as applications on the cloud. Some are of the persuasion that the true difference between these terms is marketing and branding; that the technology evolution was incremental and the marketing evolution discrete.

Characteristics
Cloud computing customers do not generally own the physical infrastructure serving as host to the software platform in question. Instead, they avoid capital expenditure by renting usage from a third-party provider. They consume resources as a service and pay only for resources that they use. Many cloud-computing offerings employ the utility computing model, which is analogous to how traditional utility services (such as electricity) are consumed, while others bill on a subscription basis. Sharing "perishable and intangible" computing power among multiple tenants can improve utilization rates, as servers are not unnecessarily left idle (which can reduce costs significantly while increasing the speed of application development). A side effect of this approach is that overall computer usage rises dramatically, as customers do not have to engineer for peak load limits. Additionally, "increased high-speed bandwidth" makes it possible to receive the same response times from centralized infrastructure at other sites.

Economics
Diagram showing economics of cloud computing versus traditional IT, including capital expenditure (CapEx) and operational expenditure (OpEx).
Cloud computing users can avoid capital expenditure (CapEx) on hardware, software, and services when they pay a provider only for what they use. Consumption is usually billed on a utility (e.g. resources consumed, like electricity) or subscription (e.g. time based, like a newspaper) basis with little or no upfront cost. A few cloud providers are now beginning to offer the service for a flat monthly fee as opposed to on a utility billing basis. Other benefits of this time sharing style approach are low barriers to entry, shared infrastructure and costs, low management overhead, and immediate access to a broad range of applications. Users can generally terminate the contract at any time (thereby avoiding return on investment risk and uncertainty) and the services are often covered by service level agreements (SLAs) with financial penalties.
According to Nicholas Carr, the strategic importance of information technology is diminishing as it becomes standardized and less expensive. He argues that the cloud computing paradigm shift is similar to the displacement of electricity generators by electricity grids early in the 20th century.
Although companies might be able to save on upfront capital expenditures, they might not save much and might actually pay more for operating expenses. In situations where the capital expense would be relatively small, or where the organization has more flexibility in their capital budget than their operating budget, the cloud model might not make great fiscal sense. Other factors impacting the scale of any potential cost savings include the efficiency of a company's data center as compared to the cloud vendor's, the company's existing operating costs, the level of adoption of cloud computing, and the type of functionality being hosted in the cloud.

Companies
Dell, Vmware, Sun Microsystems, Rackspace US, Star UK, IBM, Amazon, Google, BMC, Microsoft, Yahoo and A-Server DAAS.com are some of the major cloud computing service providers. Cloud services are also being adopted by individual users through large enterprises including Vmware, General Electric, and Procter & Gamble.

Architecture
The majority of cloud computing infrastructure, as of 2009, consists of reliable services delivered through data centers and built on servers with different levels of virtualization technologies. The services are accessible anywhere that provides access to networking infrastructure. Clouds often appear as single points of access for all consumers' computing needs. Commercial offerings are generally expected to meet quality of service (QoS) requirements of customers and typically offer SLAs. Open standards
are critical to the growth of cloud computing, and open source software has provided the foundation for many cloud computing implementations.

History
The Cloud is a term that borrows from telephony. Up to the 1990s, data circuits (including those that carried Internet traffic) were hard-wired between destinations. Subsequently, long-haul telephone companies began offering Virtual Private Network (VPN) service for data communications. Telephone companies were able to offer VPN based services with the same guaranteed bandwidth as fixed circuits at a lower cost because they could switch traffic to balance utilization as they saw fit, thus utilizing their overall network bandwidth more effectively. As a result of this arrangement, it was impossible to determine in advance precisely which paths the traffic would be routed over. The term "telecom cloud" was used to describe this type of networking, and cloud computing is conceptually somewhat similar.
Cloud computing relies heavily on virtual machines (VMs), which are spawned on demand to meet user needs. A common depiction in network diagrams is a cloud outline. The underlying concept of cloud computing dates back to 1960, when John McCarthy opined that "computation may someday be organized as a public utility"; indeed it shares characteristics with service bureaus that date back to the 1960s. The term cloud had already come into commercial use in the early 1990s to refer to large Asynchronous Transfer Mode (ATM) networks. Ill-fated startup General Magic launched a short-lived cloud computing product in 1995 in partnership with several telecommunications company partners such as AT&T, just before the consumer-oriented Internet became popular. By the turn of the 21st century, the term "cloud computing" began to appear more widely, although most of the focus at that time was limited to SaaS.
In 1999, Salesforce.com was established by Marc Benioff, Parker Harris, and their associates. They applied many technologies developed by companies such as Google and Yahoo! to business applications. They also provided the concept of "On demand" and SaaS with their real business and successful customers. The key for SaaS is that it is customizable by customers with limited technical support required. Business users have enthusiastically welcomed the resulting flexibility and speed.
In the early 2000s, Microsoft extended the concept of SaaS through the development of web services. IBM detailed these concepts in 2001 in the Autonomic Computing Manifesto, which described advanced automation techniques such as self-monitoring, self-healing, self-configuring, and self-optimizing in the management of complex IT systems with heterogeneous storage, servers, applications, networks, security mechanisms, and other system elements that can be virtualized across an enterprise.
Amazon played a key role in the development of cloud computing by modernizing their data centers after the dot-com bubble and, having found that the new cloud architecture resulted in significant internal efficiency improvements, providing access to their systems through Amazon Web Services in 2005 on a utility computing basis.
In 2007, Google, IBM, and a number of universities embarked on a large scale cloud computing research project, around the time the term started, it was a hot topic. By mid-2008, cloud computing gained popularity in the mainstream press, and numerous related events took place.
In August 2008, Gartner Research observed that "organizations are switching from company-owned hardware and software assets to per-use service-based models" and that the "projected shift to cloud computing will result in dramatic growth in IT products in some areas and in significant reductions in other areas." In 2009, Cloud Computing Solutions by Google, Amazon, Microsoft, and IBM are the most popular among users with Sun and Ubuntu following them in the Cloud.
Criticism and Disadvantages of Cloud Computing
Because cloud computing does not allow users to physically possess the storage of their data (the exception being the possibility that data can be backed up to a user-owned storage device, such as a USB flash drive or hard disk) it does leave responsibility of data storage and control in the hands of the provider.
Cloud computing has been criticized for limiting the freedom of users and making them dependent on the cloud computing provider, and some critics have alleged that it is only possible to use applications or services that the provider is willing to offer. Thus, The London Times compares cloud computing to centralized systems of the 1950s and 60s, by which users connected through "dumb" terminals to mainframe computers. Typically, users had no freedom to install new applications and needed approval from administrators to achieve certain tasks. Overall, it limited both freedom and creativity. The Times argues that cloud computing is a regression to that time.
One of the important issues in cloud computing that needs to be addressed is that once you upload your data to cloud computing service provider, you lose control over your data and if computing service provider is experiencing problems, you may not be able to access your data at all. Also, in most of the cases, at least this is true for free services; there is no one on the provider's side to assist you with a problem (if you are having one).
Similarly, Richard Stallman, founder of the Free Software Foundation, believes that cloud computing endangers liberties because users sacrifice their privacy and personal data to a third party. He stated that cloud computing is "simply a trap aimed at forcing more people to buy into locked, proprietary systems that would cost them more and more over time." Further to Stallman's observation, it would be a challenge for hosting/deploying intranet and access restricted (for Govt., defense, institutional, etc) sites and their maintenance. Commercial sites using tools such as web analytics may not be able to capture right data for their business planning etc.

Consumer & Business Trends to Accelerate Cloud Computing
Cloud computing may seem more hype than reality as the technology industry is busy refining the term. However, substantive business and market trends are catapulting cloud computing to the forefront. Companies and governments are using this emerging concept in the real world, and its uses are growing. Over the next three to five years, cloud computing will evolve and gain wider use as five major consumer and business trends accelerate.

1. The Web as a Participatory Worldwide Communications Media
Today the Web is used to exchange, contribute and work with information. No longer static as in earlier years, Web content is transformed every day by users around the world. Wikipedia, Facebook and YouTube are prominent examples but are the tip of the iceberg. Social networking, streaming audio and video, and other collaborative tools are rapidly growing behind the firewalls of company intranets. Knowledge workers, especially those working in research and development, use Web applications to collaborate on work projects across the globe.
China Telecom and Sogeti, a European professional services firm, use internal cloud computing platforms to conduct online, real-time brainstorming sessions among their workers. The high-performance platform is able to collect input from 18,000 Sogeti employees, and sort and analyze it for business use. Interactive, real-time communications, known as Web 2.0, are a major impetus for cloud computing, which meets the high-performance demands of the dynamic Web by processing massive amounts of information in a fraction of a second, using existing infrastructures.
2. The Need to Use less Energy
The goal to reduce the energy used by IT gains traction daily as costs and concerns over carbon emissions increase. Cloud computing uses IT resources more efficiently, reducing the amount of power needed to run data centers. Excess computing power is put to use, rather than being powered on, using energy, but remaining idle. According to Info-Tech Research Group, most computer servers run full time, but are used at 10 percent to 20 percent of capacity. By pooling resources, cloud-computing platforms scale up or down, saving energy and operating costs.

3. Innovation Imperative
In a global economy, the quest to be more innovative, to get new ideas to market faster and to use technology to speed up results is a major driver of cloud computing, which offers robust computer power, at lower cost, when and wherever it is needed.
At a Wuxi, China, industrial park, tenants, mostly startup software companies, are able to access an entire IT infrastructure by plugging in their computers. The industrial park worked with IBM to create a cloud-computing center, which it hosts for its tenants. IT is part of the industrial park's infrastructure, along with heat, lights and water. For software startups, this means lower costs in developing products. They avoid buying and operating their own servers, applications or tools and pay only for the IT services they actually use. Vietnam National University recently established a cloud-computing platform to build IT skills among its workforce more quickly.

4. Quest for Simplicity
Although technology grows more sophisticated, users expect it to remain simple to use. The market success of delivering software as a service over the Internet is an example of the trend toward simplicity. It is also a precursor of cloud computing. By purchasing a service rather than buying software outright, a company uses up-to-date software without the complexities and costs of managing or upgrading it.
Simplifying IT and Green Initiatives are Driving Virtualization Sponsored by CIO and IBM
Cloud computing brings similar simplicity to the entire range of IT. Some cloud-computing platforms will be hosted externally and purchased as a service. This is appealing for smaller firms that have limited technical staffs. However, many companies, especially larger firms, are likely to opt for internal platforms, especially in industries, such as finance, with security and privacy issues.

5. Structure Out of Chaos
The Web enables fast access to an immense quantity of information, but sorting it is a challenge. The success of search technologies, such as Google, attests to the need for order and structure as information expands faster than the human mind can assimilate. Google has more than 141 million visitors per month to its search site in the U.S. Every day huge numbers of Internet users contribute data, pictures, audio and blogs to websites around the world. Without the ability to find the data users need, fast and accurately, the Web's value as a productivity tool could begin to wane.
Cloud computing is tailor-made for bringing order out of chaos. It offers the ability to integrate widely diverse kinds of information, more computing power for handling massive amounts of data, and a simpler infrastructure to manage complexity. As an emerging technology, cloud computing will transform over time. Its real value is its ability to respond to major business and market trends that will remain in our technology landscape for years to come.

Political & Legal Issues

Political issues
The Cloud spans many borders and "may be the ultimate form of globalization." As such, it becomes subject to complex geopolitical issues, and providers are pressed to satisfy myriad regulatory environments in order to deliver service to a global market. This dates back to the early days of the Internet, when libertarian thinkers felt that "cyberspace was a distinct place calling for laws and legal institutions of its own".
Despite efforts (such as US-EU Safe Harbor) to harmonize the legal environment, as of 2009, providers such as Amazon Web Services cater to major markets (typically the United States and the European Union) by deploying local infrastructure and allowing customers to select "availability zones." Nonetheless, concerns persist about security and privacy from individual through governmental levels (e.g., the USA PATRIOT Act, the use of national security letters, and the Electronic Communications Privacy Act's Stored Communications Act.

Legal issues
In March 2007, Dell applied to trademark the term "cloud computing" (U.S. Trademark 77,139,082) in the United States. The "Notice of Allowance" the company received in July 2008 was canceled in August, resulting in a formal rejection of the trademark application less than a week later.
In September 2008, the United States Patent and Trademark Office (USPTO) issued a "Notice of Allowance" to CGactive LLC (U.S. Trademark 77,355,287) for "CloudOS". As defined under this notice, a cloud operating system is a generic operating system that "manage[s] the relationship between software inside the computer and on the Web", such as Microsoft Azure.
In November 2007, the Free Software Foundation released the Affero General Public License, a version of GPLv3 intended to close a perceived legal loophole associated with free software designed to be run over a network, particularly SaaS. An application service provider is required to release any changes they make to Affero GPL open source code.

Risk mitigation
• Corporations or end-users wishing to avoid not being able to access their data-or even losing it-are typically advised to research vendors' policies on data security before using their services. One technology analyst and consulting firm, Gartner, lists several security issues that one should discuss with cloud-computing vendors:
• Privileged user access-that has specialized access to data and about the hiring and management of such administrators?
• Regulatory compliance-is the vendor willing to undergo external audits and/or security certifications?
• Data location-does the provider allow for any control over the location of data?
• Data segregation-is encryption available at all stages, and was these encryption schemes designed and tested by experienced professionals?
• Recovery-what happens to data in the case of a disaster, and does the vendor offer complete restoration, and, if so, how long does that process take?
• Investigative Support-Does the vendor have the ability to investigate any inappropriate or illegal activity?
• Long-term viability-what happens to data if the company goes out of business, and is data returned and in what format?
• Data availability-Can the vendor move your data onto a different environment should the existing environment become compromised or unavailable?
In practice, one can best determine data-recovery capabilities by experiment; for example, by asking to get back old data, seeing how long it takes, and verifying that the checksums match the original data. Determining data security can be more difficult, but one approach is to encrypt the data yourself. If you encrypt data using a trusted algorithm, then, regardless of the service provider's security and encryption policies, the data will only be accessible with the decryption keys. This leads, however, to the problem of managing private keys in a pay-on-demand computing infrastructure.
Key Characteristics
• Agility improves with users able to rapidly and inexpensively re-provision technological infrastructure resources. The cost of overall computing is unchanged, however, and the providers will merely absorb up-front costs and spread costs over a longer period.
• Cost is claimed to be greatly reduced and capital expenditure is converted to operational expenditure. This ostensibly lowers barriers to entry, as infrastructure is typically provided by a third-party and does not need to be purchased for one-time or infrequent intensive computing tasks. Pricing on a utility computing basis is fine-grained with usage-based options and fewer IT skills are required for implementation (in-house). Some would argue that given the low cost of computing resources, that the IT burden merely shifts the cost from in-house to outsourced providers. Furthermore, any cost reduction benefit must be weighed against a corresponding loss of control, access and security risks.
• Device and location independence enable users to access systems using a web browser regardless of their location or what device they are using (e.g., PC, mobile). As infrastructure is off-site (typically provided by a third-party) and accessed via the Internet, users can connect from anywhere.
• Multi-tenancy enables sharing of resources and costs across a large pool of users thus allowing for:
• Centralization of infrastructure in locations with lower costs (such as real estate, electricity, etc.)
• Peak-load capacity increases (users need not engineer for highest possible load-levels)
• Utilization and efficiency improvements for systems that are often only 10-20% utilized.

• Reliability improves through the use of multiple redundant sites, which makes cloud computing suitable for business continuity and disaster recovery. Nonetheless, many major cloud computing services have suffered outages, and IT and business managers can at times do little when they are affected.
• Scalability via dynamic ("on-demand") provisioning of resources on a fine-grained, self-service basis near real-time, without users having to engineer for peak loads. Performance is monitored and consistent and loosely-coupled architectures are constructed using web services as the system interface.
• Security typically improves due to centralization of data, increased security-focused resources, etc., but concerns can persist about loss of control over certain sensitive data. Security is often as good as or better than under traditional systems, in part because providers are able to devote resources to solving security issues that many customers cannot afford. Providers typically log accesses, but accessing the audit logs themselves can be difficult or impossible. Ownership, control and access to data controlled by "cloud" providers may be made more difficult, just as it is sometimes difficult to gain access to "live" support with current utilities. Under the cloud paradigm, management of sensitive data is placed in the hands of cloud providers and third parties.
• Sustainability comes about through improved resource utilization, more efficient systems, and carbon neutrality. Nonetheless, computers and associated infrastructure are major consumers of energy. A given (server-based) computing task will use X amount of energy whether it is on-site, or off.

Components
Six layers components of cloud computing are:

Application
A cloud application leverages the Cloud in software architecture, often eliminating the need to install and run the application on the customer's own computer, thus alleviating the burden of software maintenance, ongoing operation, and support. For example:
• Peer-to-peer / volunteer computing (Bittorrent, BOINC Projects, Skype)
• Web application (Twitter)
• Software as a service (Google Apps, SAP and Salesforce)
• Software plus services (Microsoft Online Services)

Client
A cloud client consists of computer hardware and/or computer software which relies on cloud computing for application delivery, or which is specifically designed for delivery of cloud services and which, in either case, is essentially useless without it. For example:
• Mobile (Android, iPhone, Windows Mobile)
• Thin client (CherryPal, Zonbu, gOS-based systems)
• Thick client / Web browser (Microsoft Internet Explorer, Mozilla Firefox)

Infrastructure
Cloud infrastructure, such as Infrastructure as a service, is the delivery of computer infrastructure, typically a platform virtualization environment, as a service. For example:
• Full virtualization (GoGrid, Skytap, iland)
• Grid computing (Sun Cloud)
• Management (RightScale)
• Compute (Amazon Elastic Compute Cloud)
• Platform (Force.com)
• Storage (Amazon S3, Nirvanix, Rackspace)

Platform
A cloud platform, such as Platform as a service, the delivery of a computing platform, and/or solution stack as a service, facilitates deployment of applications without the cost and complexity of buying and managing the underlying hardware and software layers. For example:
• Code Based Web Application Frameworks
• Java Google Web Toolkit (Google App Engine)
• Python Django (Google App Engine)
• Ruby on Rails (Heroku)
• .NET (Azure Services Platform)
• Non-Code Based Web Application Framework
• WorkXpress
• Cloud Computing Application & Web Hosting (Rackspace Cloud)
• Proprietary (Force.com)

Service
A cloud service includes "products, services and solutions that are delivered and consumed in real-time over the Internet". For example, Web Services ("software system[s] designed to support interoperable machine-to-machine interaction over a network") which may be accessed by other cloud computing components, software, e.g., Software plus.
ervices, or end users directly. Specific examples include:
• Identity (OAuth, OpenID)
• Integration (Amazon Simple Queue Service)
• Payments (Amazon Flexible Payments Service, Google Checkout, PayPal)
• Mapping (Google Maps, Yahoo! Maps, MapQuest)
• Search (Alexa, Google Custom Search, Yahoo! BOSS)
• Video Games (OnLive, Gaikai)
• Live chat (LivePerson)
• Symplified Symplified Inc. is a privately owned American company based in Boulder, CO. Symplified was founded by the same management team that created Securant, which pioneered the market for Web access management software and was acquired for $140M by RSA Security. The company first incorporated in 2006.
• Others (Amazon Mechanical Turk)

Architecture
Cloud architecture, the systems architecture of the software systems involved in the delivery of cloud computing, comprises hardware and software designed by a cloud architect who typically works for a cloud integrator. It typically involves multiple cloud components communicating with each other over application programming interfaces, usually web services.
This closely resembles the Unix philosophy of having multiple programs doing one thing well and working together over universal interfaces. Complexity is controlled and the resulting systems are more manageable than their monolithic counterparts.
Cloud architecture extends to the client, where web browsers and/or software applications access cloud applications.
Cloud storage architecture is loosely coupled, where metadata operations are centralized enabling the data nodes to scale into the hundreds, each independently delivering data to applications or users.
Types
Public cloud
Public cloud or external cloud describes cloud computing in the traditional mainstream sense, whereby resources are dynamically provisioned on a fine-grained, self-service basis over the Internet, via web applications/web services, from an off-site third-party provider who shares resources and bills on a fine-grained utility computing basis.

Hybrid cloud
A hybrid cloud environment consisting of multiple internal and/or external providers "will be typical for most enterprises".

Private cloud
Private cloud and internal cloud are neologisms that some vendors have recently used to describe offerings that emulate cloud computing on private networks. These (typically virtualisation automation) products claim to "deliver some benefits of cloud computing without the pitfalls", capitalizing on data security, corporate governance, and reliability concerns. They have been criticized on the basis that users "still have to buy, build, and manage them" and as such do not benefit from lower up-front capital costs and less hands-on management, essentially "[lacking] the economic model that makes cloud computing such an intriguing concept".
While an analyst predicted in 2008 that private cloud networks would be the future of corporate IT, there is some uncertainty whether they are a reality even within the same firm. Analysts also claim that within five years a "huge percentage" of small and medium enterprises will get most of their computing resources from external cloud computing providers as they "will not have economies of scale to make it worth staying in the IT business" or be able to afford private clouds. Analysts have reported on Platform's view that private clouds are a stepping stone to external clouds, particularly for the financial services, and that future datacenters will look like internal clouds.
Roles

Provider
A cloud computing provider or cloud computing service provider owns and operates live cloud computing systems to deliver service to third parties. Usually this requires significant resources and expertise in building and managing next-generation data centers. Some organizations realize a subset of the benefits of cloud computing by becoming "internal" cloud providers and servicing themselves, although they do not benefit from the same economies of scale and still have to engineer for peak loads. The barrier to entry is also significantly higher with capital expenditure required and billing and management creates some overhead. Nonetheless, significant operational efficiency and agility advantages can be realized, even by small organizations, and server consolidation and virtualization rollouts are already well underway. Amazon.com was the first such provider, modernizing its data centers which, like most computer networks, were using as little as 10% of its capacity at any one time just to leave room for occasional spikes. This allowed small, fast-moving groups to add new features faster and easier, and they went on to open it up to outsiders as Amazon Web Services in 2002 on a utility computing basis.
The companies listed in the Components section are providers.
User
A user is a consumer of cloud computing. The privacy of users in cloud computing has become of increasing concern. The rights of users are also an issue, which is being addressed via a community effort to create a bill of rights. The Franklin Street statement was drafted with an eye towards protecting users' freedoms.

Vendor
Some vendors sell or give products and services that facilitate the delivery, adoption and use of cloud computing. For example:
• Computer hardware (Dell, HP, IBM, and Sun Microsystems)
• Storage (3PAR, EMC, Hitachi Data Systems, IBM, Mezeo, NetApp, ParaScale, and Sun Microsystems)
• Infrastructure (Cisco Systems, Juniper Networks, and Brocade Communications)
• Computer software (3tera, Eucalyptus, g-Eclipse, and Hadoop)
• Operating systems (Solaris, AIX, Linux including Novell, Red Hat, and Ubuntu)
• Platform virtualization (Citrix, IBM, Linux KVM, Microsoft, Sun xVM, VMware, and Xen)
Standards
Cloud standards, a number of existing, typically lightweight, open standards, have facilitated the growth of cloud computing, including:

• Application
o Communications (HTTP, XMPP)
o Security (OAuth, OpenID, SSL/TLS)
o Syndication (Atom)
• Client
o Browsers (AJAX)
o Offline (HTML 5)
• Implementations
o Virtualization (OVF)
• Platform
o Solution stacks (LAMP)
• Service
o Data (XML, JSON)
o Web Services (REST)
• Storage
Pros and cons of Cloud Computing

Pros

1. Fast start-up
"Cloud computing is really a no-brainer for any start-up because it allows you to test your business plan very quickly for little money. Every start-up, or even a division within a company that has an idea for something new, should be figuring out how to use cloud computing in its plan," says Brad Jefferson, CEO of Animoto, a New York company that creates full-motion videos out of customer-selected photos and music. "Cloud computing has changed the game for entrepreneurs -- the greatest part about it is that on launch day, you have the confidence that you scale to the world."

2. Scalability
To figure out if you're a good cloud service prospect, first consider the variability of the resource utilization of your own IT structure, says Tom Nolle, CEO of CIMI, a high-tech consulting firm. "If you've got enormous peaks and valleys, you're forced to oversupply IT resources to address the peaks. It may be significantly less costly for you to outsource the peaks," he says.

3. Business agility
"Your mind really changes quickly when you can solve problems using IT resources but you don't need a long-term commitment and you don't have to wait a long time to get them," says Michael Crandell, CEO of RightScale, a cloud management and support company. "Cloud computing changes the whole pattern of agility at a much lower cost."

4. Faster product development
Since moving some applications and data to Amazon's cloud last April, Eli Lilly & Co. has seen provisioning time drop from weeks to minutes, says Dave Powers, associate information consultant at the Indianapolis company. "If I can give scientists eight weeks back on their research, that's a huge value there," he adds. "This is really starting to impact how we do business. We're starting to reduce cycle times in research, which is critical for us. That's a trickle-down effect of technology that we can make available to the scientific community."

5. No capital expenditures
Are you out of space in your data centre? Have your applications outgrown the infrastructure? Cloud computing services allow a company to shift from capital to operational expenses even in do-or-die cases, says Bernard Golden, CEO of HyperStratus, a consulting firm specializing in advanced IT technologies.

Cons
1. Bandwidth could bust your budget
Such was the case at Sony Pictures Image Works, which considered then ruled out an external cloud service to address storage scalability challenges, says Nick Bali, senior systems engineer at the Culver City, Calif., company. Every day, Sony animators access and generate between 4 and 12 terabytes of data. "The network bandwidth we'd need to put that into someone's cloud and to read it back is tremendous and the cost would be so large that we might as well buy the storage ourselves rather than paying someone else for it," he says. Now Sony is evaluating a private storage cloud, using ParaScale's cloud storage software.

2. App performance could suffer
A private cloud might, but a public cloud definitely wouldn't lead to improved application performance -- not when taking network latency into account, says Tony Bishop, CEO of Adaptivity, a consulting firm specializing in next-generation IT infrastructure. "I couldn't see an investment bank putting a latency-sensitive application on an external cloud," adds Steve Harriman, a vice president at NetQoS.

3. Data might not be cloud-worthy
"On Day 1, we probably had eight to 10 applications that we would have loved to take into the cloud," says Eli Lilly's Powers. "But, knowing the type of data we had and the classification [of who could see it], we decided going through internal governance and rigor around taking care of that data would be appropriate." And, definitely don't put an application that provides competitive advantage or contains customer-sensitive information in the public cloud, Bishop adds.

4. Too big to scale
"The bigger you are, the bigger your IT resource pool. And the bigger your IT resource pool, the less likely it is that you'll see any enormous financial advantage in outsourcing to the cloud," CIMI's Nolle says. "Cloud computing promotes better resource utilization, but the gains are greatest when moving from relatively small consumption of resources upwards. If you're a very large enterprise, you might find you can achieve better economy by doing your own cloud than going to an outsourced one."

5. Human capital may be lacking
Exploring next-generation IT models requires an adventuresome spirit and technical astuteness, says HyperStratus' Golden. "If you don't have the human capital that's willing to stretch and learn new things, taking on cloud computing can be very frustrating."

References
http://en.wikipedia.org/wiki/Cloud_computing
www.networkworld.com/supp/.../..//051809-cloud-pro-con.html
http://www.sun.com/solutions/cloudcomputing/index.jsp

Disclaimer
Views expressed in this article are generally accumulated from published material from the internet especially from Wikipedia. The article also contains major excerpts from internet magazines and other PDF documents.

About the Writer
Mr. Zaki Rashidi is a contributing editor of @internet magazine. He is assistant professor at FAST-School of Business, Karachi.