Commercial web applications
The major advantage of web application development based on standard browser features is their ability to work as intended, regardless of operating system or its version installed on the client computer. Instead of writing application version for Windows, Linux, Mac OS X and other operating systems, you can theoretically create the application once and offer it almost anywhere. However, in practice, inconsistent implementation of HTML, CSS, DOM, and other specifications of particular browsers cause problems. Moreover, users have the option to set the display method in their browser (for example, choose a different typeface, font size, font colour, or disable scripting support), which may interfere with the uniform application design.
Another but less common option is the use of Macromedia Flash or Java applets for a part or an entire user interface. As this technology is supported by most Web browsers (usually in the form of plug-ins), the applications based on Flash or Java can be in fact developed and implemented everywhere easily. Though they provide developers with more control over the user interface and can overcome a number of problems with the settings of browsers, the differences in particular implementations of Flash or Java may cause other complications. For the similarity of their architecture with traditional client-server applications with a sort of thin client, there are doubts whether the systems of this type can be called ""web applications"" or whether use the term Rich Internet Application instead.
The obvious drawback of this approach is the high dependence on the provider application and the need of sufficient bandwidth on the server provider side. If the provider decides to stop providing this service, or it is interrupted for any other reason, it is not possible to continue using the service, as opposed to locally operated software. Likewise, if the connection with the server provider is interrupted, the service may be temporarily unavailable. These disadvantages are outweighed by the advantage of almost zero maintenance and minimal cost - the customer usually pays only a fixed monthly or annual fee.