Standard Widget Toolkit (SWT):

SWT is an open source widget tool kit for developing rich, efficient and portable GUI applications. It was originally developed by IBM and being maintained by Eclipse Foundation along with Eclipse IDE. It is an alternative to AWT and Swing. To display the elements, it implements the operating system GUI libraries by using Java Native Interface. The SWT applications are portable and unique for each platform.

The need of SWT is to provide a common API for accessing different operating system / platform specific widgets. The goal for designing of SWT is high performance, native OS look and feel, and platform integration. Swing on the other hand, designed to allow for a highly customizable look and feel that is common across different platforms.

JFace:

A User Interface project developed by Eclipse to handle most commonly used User Interface tasks. It is window based system independent in both implementation and API. It is designed to work with SWT. JFace is included with images, text, dialog, wizard, images, font registries and progress reporting for long running operations.

JFace has two mechanisms – namely action and viewing.

The mechanism of actions allows the commands to be defined independently by the user from the exactness of whereabouts in the User Interface.

The mechanism of viewing is based on the adapters for certain SWT widgets, which simplifies the application presentation data structured with lists, tables or trees.

Eclipse runtime kernel is connected with few classes that have JFace. It can be a common practice to extract JFace and SWT to be used for stand-alone java applications which is not based on the Eclipse runtime.