I had a big interest in RIA at the time. The big players were Adobe AIR, Microsoft Silverlight, Eclipse RCP, Netbeans, and I also considered JavaFX--I might be forgetting another one.

Silverlight had the best performance/fit for my purposes and sadly was the first of many to go away, largely due to the popularity of iPhone and these platform/tools being excluded. Too bad Apple only promotes Apple's innovations and actively suppresses others.