UltraLightClient (ULC) is an add-on library for Swing and J2EE that allows the use of Swing in thin client architecture. With ULC, apps are hosted in an appserver much like HTML based apps, with only a Presentation Engine on the desktop, which displays the user interface and forwards user interactions to the server. The entire state of the application is maintained on the server. The Presentation Engine is conceptually stateless but caches state for immediate access to increase performance.

New in UltraLightClient 6.0 are the ability to pause and resume a user session including its editing state, e.g. current windows opened, selections, and scroll positions. Other new features include action support for components with action listeners, a new Border API, and full support of Swing layouts.

As the CEO of Canoo, I'd love to hear opinions on where the half-object + protocol design pattern approach as chosen by UltraLightClient is considered better than the code shipping approach followed by products like Flex. Or, put differently: which application scenarios for Rich Internet Applications (RIA) are suited for code shipping and which for HOPP?

DevX has published a review on Canoo's UltraLightClient:
http://www.devx.com/Java/Article/28909

For more infos on UltraLightClient see:
http://www.canoo.com/ulc/