Try the latest version of Google Desktop Gadget Designer, a Windows application that's part of the Google Desktop SDK. With the designer I have my whole development process in one place and one window: javascript coding, xml editing and buttons arranging. A preview is just an F5 push away and I get the whole thing packed up with F7. It doesn't get any easier than that... errr, okay, it will probably directly parse human thoughts in the future.

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