At the moment, the only fully supported language, and the de-facto standard for DOM tree manipulation in the browser is JavaScript. It looks like it has deep design issues t
No. JavaScript is it, but it will evolve. The next version is "JavaScript Harmony," and you can learn more if you Google that.
Now and then someone suggests putting a byte code interpreter into the browsers alongside JavaScript. Probably won't happen, at least for awhile.
I happen to love JavaScript. But there are other solutions, including GWT, which compiles Java to JavaScript and Script#, which compiles C# to JavaScript.