Wikipedia
Tersus Visual Programming Platform is a general purpose software development platform that enables the development of applications, mainly rich web applications, by drawing flow diagrams instead of writing code. It is dual licensed as open-source and proprietary software.
The Tersus Modeling Language is a visual language for defining user interface, client side behavior and server side processing. The language shares many features of dataflow programming languages.
When used for web development, Tersus can be classified as Client Side + Server Side (using AJAX techniques). The modeled applications are executed by the Tersus Server.
Tersus Studio is an IDE, an extension of the Eclipse platform, used by developers (modelers) to graphically define the functionality of applications.
The platform also contains a visual debugging capability. The Tersus Server can record every step during the application’s execution, and this recording ("trace") can then be played back in the Tersus Studio to view the flow of the application and the value of each data element.
Both the Studio and the Server are available on a variety of platforms, including Microsoft Windows, UNIX, Linux, and Mac OS X. The latest stable version of Tersus is version 2.1.31.4, released August 27, 2014.
The Tersus Visual Programming Platform version is published under the GPL v2 license. There's also a Tersus Enterprise Platform version under a commercial license providing additional integration features and support.