TouchDevelop runs in IE10, Chrome (including on Android), Firefox, Safari (on Mac and iOS). You can run apps you create right away, inside TouchDevelop, in the browser.
If you want to sell them, then they will run on Windows Phone, Windows RT and Windows 8. To submit them to the store you will need a Windows 8 PC and a dev account.
If you want to sell them, then they will run on Windows Phone, Windows RT and Windows 8. To submit them to the store you will need a Windows 8 PC and a dev account.