Having been working inside an IDE for a while now, I felt very unproductive, when I recently made the switch to Ruby development for a living. In the past 6 months or so, I have tried every Ruby IDE out there and I found all of them to be lacking in quality. I was quite frustrated especially when editing rhtml files and the IDE would crawl to a halt and in some cases even run out of memory.
As a web developer, you probably have a few extensions that you have loaded like Firebug, Web developer etc that help debug your web app. Every now and then you may also have to reset the cache, cookies and any other settings in you browser to test some bug. This can be a real pain, considering that you use the same browser for checking your email, stock quotes or even do web banking etc.
In Mustang build 38, the AWT team integrated a major improvement to the Modality system in AWT/Swing. This was a set of RFEs that had about 475 total votes on the Bug Parade.
Hi-Fi Swing (or improving the native fidelity of Swing System L&Fs)
One of the biggest strengths of Swing is the lack of a rigid coupling
between the underlying platform toolkit and the Swing API.