The world is experiencing a technology shift. In 2012, touchscreen-based mobile devices, namely smartphones and tablets, will outsell desktops, laptops, and netbooks combined. Powerful, easy-to-use smartphones are likely to be the first and, especially in developing countries, possibly the only computing devices that virtually everyone will own and carry at all times. Is it possible to develop new software directly on these mobile devices, without using a PC? What would a user interface for such a new development model look like?

In this presentation, we present a new tool from Microsoft Research, TouchDevelop, that tries to address these questions. TouchDevelop is an application-creation environment that runs on the smartphone itself-no separate PC required. Its programming language and code editor have been built from scratch around the idea that all code is entered via a touchscreen, without a keyboard. We report on how TouchDevelop is being used today by thousands of people.