DeFacto Standard is Visual Studio Express (free with basic info). Allows you to develop in any of the Windows 8 UI supported languages, including Javascript. About halfway done with my first game (a visual novel), and I could see where down the line being able to pick up my work wherever I am and whenever I have a few minutes could be very useful. Would love to setup an IDE pointing to Dropbox for assets etc. Of course I am hopeful that the Surface Pro will make this a little more possible as well.