Thick Clients
Traditionally thick clients have been used for providing rich user interface functionalities and also for mobile workers who would like to execute functions without connecting to the network or firewall. The major characteristics are;

• Offline Working
• Higher Multimedia Requirements

However, enterprises have slowly moved away from thick clients due to the fact that building business logic and intelligence on fat clients and keeping it updated is a difficult task, as the business rules change more often than the user interface and multimedia needs and keeping it in sync with several client machines is a daunting task.

The term thick clients can be interchangeably used with ‘fat clients' or ‘rich clients.'

Cloud and Thick Clients
With the concept of delivering ‘Everything as a Service' and access to information using standardized interfaces, cloud computing opens the doors for rich thick client applications to be part of application landscape again for specific needs. Some of the features of cloud computing that support the usage of thick clients again are:

• Cloud is here to be consumed not only by traditional multi tiered applications, but more for smart devices, which are typically thick clients
• Standards-based API support the creation of thick clients using multiple technologies and rendering devices
• SaaS-based applications will allow the thick clients to concentrate on rich user interface functionality and rendering while leaving the business rules with cloud, leaving the maintenance much simpler than earlier.
• Users can access both cloud and conventional computing services
• Mobility and offline use. Fast Internet access is still not pervasive. Users can work with locally installed applications even when offline
• Performance and additional capabilities. Users can run graphics and compute-intensive workloads on the client. Without local execution, this would be slow or impossible.

Popular Thick Clients That Could Emerge Out of Cloud
1. WPF - Windows Presentation Foundation:

• As always Microsoft's dominance on the rich client and desktop is reflected in the features and ease of development of WPF applications
• Provides a unified support for:

o Graphical interface, e.g., forms and controls

o On-screen documents

o Fixed-format documents

o Images

o Video and audio

o Two-dimensional graphics

o Three-dimensional graphics

• WPF based clients can access the APIs exposed by Windows Azure and hence can access the business logic on the Cloud

2. Widget / Gadget Framework:

• Windowscontains mini-programs calledgadgets, which offer information at a glance and provide easy access to frequently used tools. For example, you can use gadgets to display a picture slide show or view continuously updated headlines.
• The Google Desktop APIs let you create gadgets, indexing plug-ins, and more for Google Desktop. You can also integrate Google Desktop search into your own applications.
• Google Gadget APIs can be used to create Gadgets that can run on multiple smart devices as thick client and yet connect to Cloud to access the enterprise data
• The Gadget APIs can connect to Cloud using the APIs exposed, making them highly extensible, while providing the flexibility of running it locally

3. Applets / Application Clients In Java EE World:

• A web page received from the web tier can include an embedded applet. Anappletis a small client application written in the Java programming language that executes in the Java virtual machine installed in the web browser. However, client systems will likely need the Java Plug-in and possibly a security policy file for the applet to successfully execute in the web browser.
• Anapplication clientruns on a client machine and provides a way for users to handle tasks that require a richer user interface than can be provided by a markup language. It typically has a graphical user interface (GUI) created from the Swing or the Abstract Window Toolkit (AWT) API, but a command-line interface is certainly possible.
• With the support of Web Services and SOAP-based APIs as part of Java EE, thick clients in Java EE can connect to Cloud to provide the desired functionality

Summary
Application software of the future will likely have a piece that runs on clients and a piece that runs in the Cloud."... "The client piece needs to be useful when disconnected from the cloud and need to get the data from the cloud on a need basis. This makes the return of thick clients real for the enterprise applications with specific characteristics.

Several of the cloud management tools are targeted to be Thick clients for above mentioned advantages. Thick clients complement cloud computing, providing localized processing to optimize the user experience as well as mobile and offline computing.

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