About Implementation of VCDiff (RFC 3284) in Javascript. Can be run on client or server. Current implementation was ported to javascript from http://code.google.com/p/diffable/ project. According to RFC 3284: "The VCDIFF Generic Differencing and Compression Data Format." Javascript implementation uses regular Array for deltas.

Usage. Say we have two strings: "abcdef" "defghiabc" and we want to calculate diff between them. Code will be as follows:

var vcd = new diffable.Vcdiff(), delta;
vcd.blockSize = 3; //setting blockSize to 3 (defaults to 20)
delta = vcd.encode('abcdef', 'defghiabc');
console.log(delta); // [3, 3, 'ghi', 0, 3]

//if we want to decode data from original string and delta:

console.log(vcd.decode('abcdef', delta)); //'defghiabc'