A series of PRNGs from http://baagoe.com/en/RandomMusings/javascript/. Speeds at: http://jsperf.com/prng-comparison

alea.js

// From http://baagoe.com/en/RandomMusings/javascript/
function Alea() {
  return (function(args) {
    // Johannes Baagøe <[email protected]>, 2010
    var s0 = 0;
    var s1 = 0;
    var s2 = 0;
    var c = 1;

    if (args.length == 0) {
      args = [+new Date];
    }
    var mash = Mash();
    s0 = mash(' ');
    s1 = mash(' ');
    s2 = mash(' ');

    for (var i = 0; i < args.length; i++) {
      s0 -= mash(args[i]);
      if (s0 < 0) {
        s0 += 1;
      }
      s1 -= mash(args[i]);
      if (s1 < 0) {
        s1 += 1;
      }
      s2 -= mash(args[i]);
      if (s2 < 0) {
        s2 += 1;
      }
    }
    mash = null;

    var random = function() {
      var t = 2091639 * s0 + c * 2.3283064365386963e-10; // 2^-32
      s0 = s1;
      s1 = s2;
      return s2 = t - (c = t | 0);
    };
    random.uint32 = function() {
      return random() * 0x100000000; // 2^32
    };
    random.fract53 = function() {
      return random() + 
        (random() * 0x200000 | 0) * 1.1102230246251565e-16; // 2^-53
    };
    random.version = 'Alea 0.9';
    random.args = args;
    return random;

  } (Array.prototype.slice.call(arguments)));
};

kiss07.js

// From http://baagoe.com/en/RandomMusings/javascript/
function KISS07() {
  return (function(args) {
    // George Marsaglia, 2007-06-23
    //http://groups.google.com/group/comp.lang.fortran/msg/6edb8ad6ec5421a5
    var x = 123456789;
    var y = 362436069;
    var z =  21288629;
    var w =  14921776;
    var c = 0;

    if (args.length == 0) {
      args = [+new Date];
    }
    var mash = Mash();
    for (var i = 0; i < args.length; i++) {
      x ^= mash(args[i]) * 0x100000000; // 2^32
      y ^= mash(args[i]) * 0x100000000;
      z ^= mash(args[i]) * 0x100000000;
      w ^= mash(args[i]) * 0x100000000;
    }
    if (y === 0) {
      y = 1;
    }
    c ^= z >>> 31;
    z &= 0x7fffffff;
    if ((z % 7559) === 0) {
      z++;
    }
    w &= 0x7fffffff;
    if ((w % 7559) === 0) {
      w++;
    }
    mash = null;

    var uint32 = function() {
      var t;

      x += 545925293;
      x >>>= 0;

      y ^= y << 13;
      y ^= y >>> 17;
      y ^= y << 5;

      t = z + w + c;
      z = w;
      c = t >>> 31;
      w = t & 0x7fffffff;

      return x + y + w >>> 0;
    };

    var random = function() {
      return uint32() * 2.3283064365386963e-10; // 2^-32
    };
    random.uint32 = uint32;
    random.fract53 = function() {
      return random() +
        (uint32() & 0x1fffff) * 1.1102230246251565e-16; // 2^-53
    };
    random.args = args;
    random.version = 'KISS07 0.9';

    return random;
  } (Array.prototype.slice.call(arguments)));
};

kybos.js

// From http://baagoe.com/en/RandomMusings/javascript/
function Kybos() {
  return (function(args) {
    // Johannes Baagøe <[email protected]>, 2010
    var s0 = 0;
    var s1 = 0;
    var s2 = 0;
    var c = 1;
    var s = [];
    var k = 0;

    var mash = Mash();
    var s0 = mash(' ');
    var s1 = mash(' ');
    var s2 = mash(' ');
    for (var j = 0; j < 8; j++) {
      s[j] = mash(' ');
    }

    if (args.length == 0) {
      args = [+new Date];
    }
    for (var i = 0; i < args.length; i++) {
      s0 -= mash(args[i]);
      if (s0 < 0) {
        s0 += 1;
      }
      s1 -= mash(args[i]);
      if (s1 < 0) {
        s1 += 1;
      }
      s2 -= mash(args[i]);
      if (s2 < 0) {
        s2 += 1;
      }
      for (var j = 0; j < 8; j++) {
        s[j] -= mash(args[i]);
        if (s[j] < 0) {
          s[j] += 1;
        }
      }
    }

    var random = function() {
      var a = 2091639;
      k = s[k] * 8 | 0;
      var r = s[k];
      var t = a * s0 + c * 2.3283064365386963e-10; // 2^-32
      s0 = s1;
      s1 = s2;
      s2 = t - (c = t | 0);
      s[k] -= s2;
      if (s[k] < 0) {
        s[k] += 1;
      }
      return r;
    };
    random.uint32 = function() {
      return random() * 0x100000000; // 2^32
    };
    random.fract53 = function() {
      return random() +
        (random() * 0x200000 | 0) * 1.1102230246251565e-16; // 2^-53
    };
    random.addNoise = function() {
      for (var i = arguments.length - 1; i >= 0; i--) {
        for (j = 0; j < 8; j++) {
          s[j] -= mash(arguments[i]);
          if (s[j] < 0) {
            s[j] += 1;
          }
        }
      }
    };
    random.version = 'Kybos 0.9';
    random.args = args;
    return random;

  } (Array.prototype.slice.call(arguments)));
};

lfib.js

// From http://baagoe.com/en/RandomMusings/javascript/
function LFib() {
  return (function(args) {
    // Johannes Baagøe <[email protected]>, 2010
    var k0 = 255,
        k1 = 52,
        k2 = 0;
    var s = [];

    var mash = Mash();
    if (args.length === 0) {
      args = [+new Date()];
    }
    for (var j = 0; j < 256; j++) {
      s[j] = mash(' ');
      s[j] -= mash(' ') * 4.76837158203125e-7; // 2^-21
      if (s[j] < 0) {
        s[j] += 1;
      }
    }
    for (var i = 0; i < args.length; i++) {
      for (var j = 0; j < 256; j++) {
        s[j] -= mash(args[i]);
        s[j] -= mash(args[i]) * 4.76837158203125e-7; // 2^-21
        if (s[j] < 0) {
          s[j] += 1;
        }
      }
    }
    mash = null;

    var random = function() {
      k0 = (k0 + 1) & 255;
      k1 = (k1 + 1) & 255;
      k2 = (k2 + 1) & 255;

      var x = s[k0] - s[k1];
      if (x < 0.0) {
        x += 1.0;
      }
      x -= s[k2];
      if (x < 0.0) {
        x += 1.0;
      }
      return s[k0] = x;
    }

    random.uint32 = function() {
      return random() * 0x100000000 >>> 0; // 2^32
    };
    random.fract53 = random;
    random.version = 'LFib 0.9';
    random.args = args;

    return random;
  } (Array.prototype.slice.call(arguments)));
};

lfib4.js

// From http://baagoe.com/en/RandomMusings/javascript/
function LFIB4() {
  return(function(args) {
    // George Marsaglia's LFIB4,
    //http://groups.google.com/group/sci.crypt/msg/eb4ddde782b17051
    var k0 = 0,
        k1 = 58,
        k2 = 119,
        k3 = 178;

    var s = [];

    var mash = Mash();
    if (args.length === 0) {
      args = [+new Date()];
    }
    for (var j = 0; j < 256; j++) {
      s[j] = mash(' ');
      s[j] -= mash(' ') * 4.76837158203125e-7; // 2^-21
      if (s[j] < 0) {
        s[j] += 1;
      }
    }
    for (var i = 0; i < args.length; i++) {
      for (var j = 0; j < 256; j++) {
        s[j] -= mash(args[i]);
        s[j] -= mash(args[i]) * 4.76837158203125e-7; // 2^-21
        if (s[j] < 0) {
          s[j] += 1;
        }
      }
    }
    mash = null;

    var random = function() {
      var x;

      k0 = (k0 + 1) & 255;
      k1 = (k1 + 1) & 255;
      k2 = (k2 + 1) & 255;
      k3 = (k3 + 1) & 255;

      x = s[k0] - s[k1];
      if (x < 0) {
        x += 1;
      }
      x -= s[k2];
      if (x < 0) {
        x += 1;
      }
      x -= s[k3];
      if (x < 0) {
        x += 1;
      }

      return s[k0] = x;
    }

    random.uint32 = function() {
      return random() * 0x100000000 >>> 0; // 2^32
    };
    random.fract53 = random;
    random.version = 'LFIB4 0.9';
    random.args = args;

    return random;
  } (Array.prototype.slice.call(arguments)));
};

mash.js

// From http://baagoe.com/en/RandomMusings/javascript/
// Johannes Baagøe <[email protected]>, 2010
function Mash() {
  var n = 0xefc8249d;

  var mash = function(data) {
    data = data.toString();
    for (var i = 0; i < data.length; i++) {
      n += data.charCodeAt(i);
      var h = 0.02519603282416938 * n;
      n = h >>> 0;
      h -= n;
      h *= n;
      n = h >>> 0;
      h -= n;
      n += h * 0x100000000; // 2^32
    }
    return (n >>> 0) * 2.3283064365386963e-10; // 2^-32
  };

  mash.version = 'Mash 0.9';
  return mash;
}

mrg32k3a.js

// From http://baagoe.com/en/RandomMusings/javascript/
function MRG32k3a() {
  return (function(args) {
    // Copyright (c) 1998, 2002 Pierre L'Ecuyer, DIRO, Université de Montréal.
    // http://www.iro.umontreal.ca/~lecuyer/
    var m1 = 4294967087;
    var m2 = 4294944443;
    var s10 = 12345,
        s11 = 12345,
        s12 = 123,
        s20 = 12345,
        s21 = 12345,
        s22 = 123;

    if (args.length === 0) {
      args = [+new Date()];
    }
    var mash = Mash();
    for (var i = 0; i < args.length; i++) {
      s10 += mash(args[i]) * 0x100000000; // 2 ^ 32
      s11 += mash(args[i]) * 0x100000000;
      s12 += mash(args[i]) * 0x100000000;
      s20 += mash(args[i]) * 0x100000000;
      s21 += mash(args[i]) * 0x100000000;
      s22 += mash(args[i]) * 0x100000000;
    }
    s10 %= m1;
    s11 %= m1;
    s12 %= m1;
    s20 %= m2;
    s21 %= m2;
    s22 %= m2;
    mash = null;

    var uint32 = function() {
      var m1 = 4294967087;
      var m2 = 4294944443;
      var a12 = 1403580;
      var a13n = 810728;
      var a21 = 527612;
      var a23n = 1370589;

      var k, p1, p2;

      /* Component 1 */
      p1 = a12 * s11 - a13n * s10;
      k = p1 / m1 | 0;
      p1 -= k * m1;
      if (p1 < 0) p1 += m1;
      s10 = s11;
      s11 = s12;
      s12 = p1;

      /* Component 2 */
      p2 = a21 * s22 - a23n * s20;
      k = p2 / m2 | 0;
      p2 -= k * m2;
      if (p2 < 0) p2 += m2;
      s20 = s21;
      s21 = s22;
      s22 = p2;

      /* Combination */
      if (p1 <= p2) return p1 - p2 + m1;
      else return p1 - p2;
    };

    var random = function() {
      return uint32() * 2.3283064365386963e-10; // 2^-32
    };
    random.uint32 = uint32;
    random.fract53 = function() {
      return random() +
        (uint32() & 0x1fffff) * 1.1102230246251565e-16; // 2^-53
    };
    random.version = 'MRG32k3a 0.9';
    random.args = args;

    return random;
  } (Array.prototype.slice.call(arguments)));
};

xorshift03.js

// From http://baagoe.com/en/RandomMusings/javascript/
function Xorshift03() {
  return (function(args) {
    // George Marsaglia, 13 May 2003
    // http://groups.google.com/group/comp.lang.c/msg/e3c4ea1169e463ae
    var x = 123456789,
        y = 362436069,
        z = 521288629,
        w = 88675123,
        v = 886756453;

    if (args.length == 0) {
      args = [+new Date];
    }
    var mash = Mash();
    for (var i = 0; i < args.length; i++) {
      x ^= mash(args[i]) * 0x100000000; // 2^32
      y ^= mash(args[i]) * 0x100000000;
      z ^= mash(args[i]) * 0x100000000;
      v ^= mash(args[i]) * 0x100000000;
      w ^= mash(args[i]) * 0x100000000;
    }
    mash = null;

    var uint32 = function() {
      var t = (x ^ (x >>> 7)) >>> 0;
      x = y;
      y = z;
      z = w;
      w = v;
      v = (v ^ (v << 6)) ^ (t ^ (t << 13)) >>> 0;
      return ((y + y + 1) * v) >>> 0;
    }

    var random = function() {
      return uint32() * 2.3283064365386963e-10; // 2^-32
    };
    random.uint32 = uint32;
    random.fract53 = function() {
      return random() +
        (uint32() & 0x1fffff) * 1.1102230246251565e-16; // 2^-53
    };
    random.version = 'Xorshift03 0.9';
    random.args = args;
    return random;

  } (Array.prototype.slice.call(arguments)));
};