It just renders 10,000 rectangles of the size of the browser window, which by itself is enough to DOS; to make it a bit worse, it also uses a large texture and adresses it with very little respect for memory locality ;-)

The C# code is here: http://people.mozilla.org/~bjacob/SilverLight5DOSJustLikeWeb... And the pixel shader: http://people.mozilla.org/~bjacob/SilverLight5DOSJustLikeWeb...

EDIT: I forgot to mention that this is very similar to the WebGL DOS example, https://cvs.khronos.org/svn/repos/registry/trunk/public/webg...