Release 10.1A: OpenEdge Getting Started:
OpenEdge Reference Architecture

Presentation Layer technologies

The primary purpose of the Presentation Layer is to allow independence of the user interface from the underlying business logic. This enables the migration of the application from one user interface to another. It also enables the underlying business logic to support more than one user interface technology.

For example, the Presentation Layer can support a variety of hardware types, including desktop computers, tablet computers, Personal Digital Assistants (PDAs), cell phones, or specialized hardware such as barcode scanners. Cross-platform hardware support is possible because Presentation Layer components can be implemented by a variety of client-rendering technologies including the Progress 4GL, .NET, Java, HTML, cHTML/WML and so on.

The determination of which technology or technologies an application supports is typically driven by user and business requirements.

While there are a number of technologies providing the means of delivering an application to an end user, the general strategies for designing a Presentation Layer are consistent across all platforms.