BF.js

function BF (code, get, print) {
eval("var i=0,d={0:0};"+code.replace(/[^\[\]\-\+\,\.\<\>]/g, "").replace(/\]/g, "}").replace(/\[/g, "while(d[i]) {").replace(/\-/g, "d[i]--;").replace(/\+/g, "d[i]++;").replace(/\</g, "i--;d[i]=d[i]?d[i]:0;").replace(/\>/g, "i++;d[i]=d[i]?d[i]:0;").replace(/\,/g, "d[i]=get();").replace(/\./g, "print(d[i]);"));
}