Kinect for Windows SDK
Whether you're educating students, entertaining friends, or exploring what's possible when humans and computers interact, you can create something amazing with Kinect for Windows. What will you develop? Download the software development kit and get started today. It includes APIs, sample code, and drivers for using Kinect sensor technology.
 

Kodu

Kodu is an exciting program that enables children to create their own 3-D video games—even if they have never programmed before. The included tools help children express themselves creatively and learn technology skills while having fun sharing, playing, and making games.
 

TouchDevelop
Program your phone by using your phone with TouchDevelop—you don't need a separate PC! Scripts can perform various tasks similar to regular apps. Any TouchDevelop user can install, run, edit, publish scripts, and share them with other people.   
 

.NET Gadgeteer 

Build devices made up of components like sensors, lights, switches, displays, communications modules, motor controllers, and much more. Just pick your components, plug them into a mainboard, and program the way they work together.

Microsoft Academic Search

Find information about academic papers, authors, conferences, journals, and organizations from multiple sources. 

Pex for Fun

Pex for fun brings programming in C#, Visual Basic, and F# to your web browser. Try your hand at writing the code to solve the puzzle and then have Pex for Fun compile, run, and analyze your code. You can also practice your coding skills by playing coding duels, in which users compete to discover a secret puzzle implementation.

Photosynth
Photosynth creates an amazing experience with nothing more than a selection of ordinary photos. It is a powerful set of tools for capturing and viewing the world in 3-D and for creating immersive 3-D experiences: synths and panoramas. Share these views with your friends on Facebook, publish them to Bing Maps, and embed them in your own website.

Robotics Developer Studio

Robotics Developer Studio is a Windows-based programming environment that makes it easy to create robotics applications across a wide variety of hardware. It includes a set of visual authoring and simulation tools, as well as templates, tutorials, and sample code to help you get started.

Try F#
F# is a programming language that is being used in enterprises and personal software development. F# combines the advantages of typed functional programming with a basis in the object-oriented and scripting environments. It can also be used for parallel programming, and has new features that are ideal for data-rich access on the web. Try F# is a website that runs on any browser and has tutorials, tools, and resources for learning the language on any computer. Try it out, then download the full system with Microsoft Visual Studio on Windows, or with MonoDevelop on Macs and Linux. 

WorldWide Telescope

WorldWide Telescope is a Web 2.0 visualization software environment. It enables your computer to function as a virtual telescope, bringing together imagery from the best ground- and space-based telescopes in the world. Experience narrated guided tours from astronomers and educators featuring interesting places in the sky, explore, and understand the universe like never before.