Thick, Thin and Ultra-thin client technology explained

Before we developed Omnis Web Client Technology, Omnis could only deliver “thick client” applications – these are applications that can only be accessed by end-users on the desktop or local network and require the Omnis Studio runtime (a cut-down version of the full Omnis Studio executable) in order to run.

In 1999, we developed the Omnis thin client to address the growing need for end users to access information via local networks and the internet. There are many advantages in the use of Web-enabled applications including the ability to install, update and maintain such applications without installing software on hundreds or even thousands of end-user’s computers.

Web applications also remove or neutralize many platform considerations or incompatibilities often found with desktop applications. Web applications only need to support common Web browsers such as Internet Explorer, Firefox, and Safari, under the most widely used platforms; namely Windows, Mac OS X and Linux – if your Web interface supports all of these browsers and platforms, then in effect so does your application.

Omnis Web Applications can also be augmented with other technologies such as Javascript and Flash if required.

To access an Omnis Thin Client application, a relatively small one-off download is required in order to install the Web Client plug-in (an ActiveX component for Internet Explorer browsers or a Netscape type plug-in for other browsers including Firefox and Safari). This can be performed either by end-users themselves or can be controlled by a company’s IT department.

A simple script can also be used in your HTML page to load the correct type of plug-in for the current browser and platform. The Web Client code can be embedded in a simple HTML wrapper (like any browser plug-in) using the <object> or <embed> tag. 

Once the plug-in is installed, no further software is required (in fact the Omnis Web Client plug-in updates itself once installed). As with all Web applications, the main application is located on the web server and can be updated as many times as the developer likes, and end-users will “see” any modifications the next time they access the application.

The Omnis Web Client provides a rich environment for you to build Web applications and a more interactive experience for your end users than plain HTML. The Web Client itself is a browser plug-in capable of presenting a complete application window as a single form (remote form class) within the user’s browser. Web applications delivered in the Web Client plug-in look and behave just like desktop applications.

The Omnis Web Client, or more specifically the Omnis remote form, could be considered as a “black box” in the sense that the end user cannot get “inside” the application or form that is presented in their browser.This provides security benefits since the end-user cannot reveal any substantial source code and the plug-in itself cannot be attacked or compromised, providing the server hosting the application is protected in the proper way.

The Omnis ‘Ultra-thin Client’ is distinguished from the the ‘Thin Client’ as it uses only standard HTML, buttons forms and entry fields to interface with the Web application, thus no browser plug-in is required to access an ultra-thin web client application. Each time the end-user accesses your web page, a new copy of the page is sent to the browser.

Both the ultra-thin and thin client techniques can be achieved using the same integrated development environment in Omnis, and neither application interface should be considered better than the other, rather- they are suited to different tasks. Indeed, some real-world applications may employ both techniques for different parts of the application. Add to these different Web capabilities in Omnis, the ability to connect to all major databases and to deploy across all platforms (Windows, Mac OS X, Linux), then hopefully you’ll agree that Omnis Studio is a very flexible and versatile development environment for creating Web applications.

Pros and Cons of using Ultra-thin


Arguments FORArguments AGAINST
HTML is a relatively simple language to use and understandLimited to standard controls - you cannot use tree lists, sliders, calendars, and other "rich" or interactive components
HTML code or files are small in file size, therefore quick to load over low bandwidth or on a low-spec PC or mobile deviceRelatively limited possibilities for layout of application, although quite a lot can be done using images and styles (CSS)
Uses standard form controls such as buttons, fields, lists, check boxes; these are ready made and built into the browser or operating system on the clientNo possibility of processing in the browser; control has to pass back to server for every method (function) to be processed
Provides a simple, familiar interface for endusersAny functionality "behind" standard controls needs to be coded from scratch
Works with virtually any browser, even older versions, on any operating system
You can use Javascript or other extended features of HTML to add interactivity to your application
HTML can be constructed on the Omnis Server dynamically using templates and data from your database and/or returned from the client

 Pros and Cons of using Web Client?

Arguments FORArguments AGAINST
Provides a rich application interface which allows you to build virtually any type of application; applications created for the Web Client look and behave the same as desktop (thick client) applicationsRequires the customer to install the Omnis Web Client plug-in, although this is only around 1 MB and can be installed automatically under Windows using a signed cab file
As well as standard field types, the Omnis Web Client has many other ready-made components, e.g. sliders, calendars, graphs, tree lists, icon arrays, etc; these components would be virtually impossible to code in pure HTML or using Javascript - and you can create your own Web componentsThe Omnis Web Client (and indeed Omnis itself) is a proprietary development and programming language - applications written for the Web Client plug-in cannot be ported to any other client such as Flash or HTML
Methods can be executed on the client so the user interface is "richer" and more interactive - this also means control does not pass back to the server every time a method is run, and therefore network traffic is reducedSome companies do not allow employees to install any kind of software off the Internet, including browser plug-ins, so the Web Client may have to be installed by IT staff or not at all
Once the Web Client plug-in is installed it is updated automatically, including new and updated components