Some open source cloud applications

1. OpenStack: Backed by Nasa, Rackspace and many other notable technology companies, OpenStack is building two separate cloud technologies: Compute, which provides the technology necessary to set up a cloud environment, and Object Storage for cloud-based storage. The goal is to develop standards that will promote interoperability among cloud offerings.

2. Eucalyptus: Eucalyptus software implements scalable IAAS-style private and hybrid clouds. Community members can also access the Eucalyptus Community Cloud where they can test the software in the cloud. 3. Cloud.com CloudStack: CloudStack makes it possible for enterprises and service providers to build and manage their own clouds. While the community version is completely open source, the enterprise and service provider editions use some proprietary code.
4. OpenProj: This open-source alternative to Microsoft Project and Primavera has been downloaded more than 1.25 million times. It's available on a SAAS basis as Projects on Demand, which claims to be "the leading Software as a Service (Seas) project solution."
5. Zimbra: Positioning itself as an alternative to Microsoft Exchange, Zimbra offers cloud-based e-mail and groupware functionality. It offers a wide array of editions and deployment options, including a SAAS edition and a VMware appliance for easy deployment on a private cloud.  

g. Cloud standards

Some sort of standards for cloud computing to increase adoption and user confidence in the cloud computing. The need for standards is to break down the walls of proprietary clouds and help cloud buyers and users avoid being tied to one vendor via lock-in.
Currently, the cloud computing market lacks true standards. Several groups have stepped forward to start working on standards for cloud computing. More information about these groups can be found in following link http://cloud-standards.org/wiki/index.php?title=Main_Page

3. Cloud computing services providers

1. Amazon: Most of the Amazon services are LAAS. It offers through Amazon Web Services (AWS): Amazon Elastic Compute Cloud (EC2), Amazon SimpleDB, Amazon CloudFront, and Amazon SQS. It claims to have 82 billion objects stored in Amazon S3 (Simple Storage Service). 

a. Amazon Web Service (AWS): It is a collection of remote computing services that together make up a cloud-computing platform, offered over the Internet by Amazon.com. The most central and well known of these services are Amazon EC2 and Amazon S3. Amazon Web Services provide online services for other web sites or client-side applications. Most of these services are not exposed directly to end users, but instead offer functionality that other developers can use.

b. Amazon Simple email Service (SES): It is a highly scalable and cost-effective bulk and transactional email-sending service for businesses and developers. Amazon SES eliminates the complexity and expense of building an in-house email solution or licensing, installing, and operating a third-party email service. The service integrates with other AWS services, making it easy to send emails from applications being hosted on services such as Amazon EC2.

c. Amazon Elastic Compute Cloud (EC2): EC2 allows users to rent virtual computers on which to run their own computer applications. EC2 allows scalable deployment of applications by providing a Web service through which a user can boot an Amazon Machine Image to create a virtual machine, which Amazon calls an "instance", containing any software desired. A user can create, launch, and terminate server instances as needed, paying by the hour for active servers, hence the term "elastic". EC2 provides users with control over the geographical location of instances that allows for latency optimization and high levels of redundancy

 Other Amazon Computing services are Amazon SimpleDB, Amazon CloudFront, and Amazon SQS

 

2. Google: Most of services are in LAAS and PAAS. Google has thousands of servers located at different locations in the world and have huge amount of information. These serves form the Google cloud and cloud-computing services makes this information accessible from any location.

Google Apps is a service from Google providing independently customizable versions of several Google products under a custom domain name. If you own a domain name, you can get started with this service by updating the MX records (DNS management section) to Goggle’s mail servers. These settings are available when you login to your dashboard at your domain name provider’s portal.

Google Apps now allows free hosting of your e-mail server (with your own domain name), up to 7.3 GB of storage per free user account, and free Google Talk, Google Calendar, Google Docs (for creating and sharing documents, spreadsheets and presentations, collaboration in real-time right inside a Web browser window), Google Sites (for easily creating and sharing a group Web site) and Start Page, and so forth. Recently, IMAP support was added to e-mail hosting, and offline support for Google Docs was added. It features several Web applications with similar functionality to traditional office suites, including: Gmail, Google Groups, Google Calendar, Talk, Docs and Sites

Google App Engine a platform for developing and hosting web applications in Google-managed data centers. Currently, the supported programming languages are Python and Java (by extension other JVM languages are also supported).

With App Engine, your application is not hosted on a single server. There are no servers to maintain: You just upload your application, and it’s ready to serve your users. Just as servicing a Google search request may involve dozens, or even hundreds of Google servers, all totally hidden and satisfied in a fraction of a second, Google App Engine applications run the same way, on the same infrastructure.

3. IBM: IBM cloud computing services offer Business Development and Test on the IBM Cloud. It is designed to augment and enhance software development and delivery capabilities, particularly in large enterprises. It also provides desktop solution and end user support. 

IBM LotusLive solutions for online collaboration, secure cloud based email, and more Information solutions for storage, business analytics and information archiving

 IBM CloudBurst with integrated storage, virtualization, networking and built-in service management systems for a variety of workloads