javascript interactiveshell with intellisense for extension development?

For extension development, is there a javascript interactive shell , that has intellisense (shows what methods and properties an开发者_开发知识库 object has) ?

Or is it possible to do this with the debugger that supports intellisense (maybe VS2008/intellij idea 9 ) ?

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Both Visual Studio 2008 and Aptana offer intellisense for Javascript. I can report that the visual studio support is rather lacking, very few of my extension's objects and functions are included and there seems to be no support for working across multiple files. I'm hoping that Aptana will be a bit better but I won't have time to try it for a while.