This page includes the sylvester library, modified to use the gpu for matrix multiply, the api is exactly the same as the orignal sylvester. Hit execute to benchmark a multiply of two 1024x1024 matrices
Open up firebug or the console to test it out
example code:
var one = $M([[1,2], [1, 2 ]]);
var two= $M([[1,2], [1, 2 ]]);
var result = one.multiply(two)
alert(result.elements);