Great Firework! From http://jsfiddle.net/licson0729/8Sgn3/light/

firework.js

window.requestAnimFrame = (function () {
    return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || function (callback) {
        window.setTimeout(callback, 1000 / 60);
    };
})();

var canvas = document.getElementById('canvas'),
    ctx = canvas.getContext('2d'),
    cw = window.innerWidth,
    ch = window.innerHeight,
    fireworks = [],
    particles = [],
    hue = 120,
    limiterTotal = 5,
    limiterTick = 0,
    timerTotal = 60,
    timerTick = 0,
    mousedown = false,
    mx,
    my;

var audio = new(window.AudioContext || window.webkitAudioContext)();
var sound, buffer;

if (!audio) {
    var xhr = new XMLHttpRequest();
    xhr.responseType = "arraybuffer";
    xhr.onload = function () {
        audio.decodeAudioData(xhr.response, function (b) {
            buffer = b;
        });
    };
    xhr.open("GET", "https://dl.dropboxusercontent.com/u/162276646/Sounds/117616__soundmary__fireworks-exploding-1.wav", true);
    xhr.send(null);
}

function playSound() {
    if (audio) {
        sound = audio.createBufferSource();
        sound.buffer = buffer;
        sound.connect(audio.destination);
        sound.playbackRate.value = random(0.6, 1.2);
        sound.play ? sound.play(0) : sound.noteOn(0);
    }
};

canvas.width = cw;
canvas.height = ch;

function random(min, max) {
    return Math.random() * (max - min) + min;
}

function calculateDistance(p1x, p1y, p2x, p2y) {
    var xDistance = p1x - p2x,
        yDistance = p1y - p2y;
    return Math.sqrt(Math.pow(xDistance, 2) + Math.pow(yDistance, 2));
}

// create firework
function Firework(sx, sy, tx, ty) {
    // actual coordinates
    this.x = sx;
    this.y = sy;
    // starting coordinates
    this.sx = sx;
    this.sy = sy;
    // target coordinates
    this.tx = tx;
    this.ty = ty;
    // distance from starting point to target
    this.distanceToTarget = calculateDistance(sx, sy, tx, ty);
    this.distanceTraveled = 0;
    // track the past coordinates of each firework to create a trail effect, increase the coordinate count to create more prominent trails
    this.coordinates = [];
    this.coordinateCount = 3;
    // populate initial coordinate collection with the current coordinates
    while (this.coordinateCount--) {
        this.coordinates.push([this.x, this.y]);
    }
    this.angle = Math.atan2(ty - sy, tx - sx);
    this.speed = 3;
    this.acceleration = 1.05
    this.brightness = random(50, 70);
    // circle target indicator radius
    this.targetRadius = 1;
}

// update firework
Firework.prototype.update = function (index) {
    // remove last item in coordinates array
    this.coordinates.pop();
    // add current coordinates to the start of the array
    this.coordinates.unshift([this.x, this.y]);

    // cycle the circle target indicator radius
    if (this.targetRadius < 8) {
        this.targetRadius += 0.3;
    } else {
        this.targetRadius = 1;
    }

    // speed up the firework
    this.speed *= this.acceleration;

    // get the current velocities based on angle and speed
    var vx = Math.cos(this.angle) * this.speed,
        vy = Math.sin(this.angle) * this.speed;
    // how far will the firework have traveled with velocities applied?
    this.distanceTraveled = calculateDistance(this.sx, this.sy, this.x + vx, this.y + vy);

    // if the distance traveled, including velocities, is greater than the initial distance to the target, then the target has been reached
    if (this.distanceTraveled >= this.distanceToTarget) {
        createParticles(this.tx, this.ty);
        // remove the firework, use the index passed into the update function to determine which to remove
        fireworks.splice(index, 1);
        playSound();
    } else {
        // target not reached, keep traveling
        this.x += vx;
        this.y += vy;
    }
}

// draw firework
Firework.prototype.draw = function () {
    ctx.beginPath();
    // move to the last tracked coordinate in the set, then draw a line to the current x and y
    ctx.moveTo(this.coordinates[this.coordinates.length - 1][0], this.coordinates[this.coordinates.length - 1][1]);
    ctx.lineTo(this.x, this.y);
    ctx.strokeStyle = 'hsl(' + hue + ', 100%, ' + this.brightness + '%)';
    ctx.stroke();

    ctx.beginPath();
    // draw the target for this firework with a pulsing circle
    ctx.arc(this.tx, this.ty, this.targetRadius, 0, Math.PI * 2);
    ctx.stroke();
}

// create particle
function Particle(x, y) {
    this.x = x;
    this.y = y;
    // track the past coordinates of each particle to create a trail effect, increase the coordinate count to create more prominent trails
    this.coordinates = [];
    this.coordinateCount = 5;
    while (this.coordinateCount--) {
        this.coordinates.push([this.x, this.y]);
    }
    // set a random angle in all possible directions, in radians
    this.angle = random(0, Math.PI * 2);
    this.speed = random(1, 10);
    // friction will slow the particle down
    this.friction = 0.95;
    // gravity will be applied and pull the particle down
    this.gravity = 1;
    // set the hue to a random number +-20 of the overall hue variable
    this.hue = random(hue - 20, hue + 20);
    this.brightness = random(10, 90);
    this.alpha = 1;
    // set how fast the particle fades out
    this.decay = random(0.006, 0.008);
}

// update particle
Particle.prototype.update = function (index) {
    // remove last item in coordinates array
    this.coordinates.pop();
    // add current coordinates to the start of the array
    this.coordinates.unshift([this.x, this.y]);
    // slow down the particle
    this.speed *= this.friction;
    // apply velocity
    this.x += Math.cos(this.angle) * this.speed;
    this.y += Math.sin(this.angle) * this.speed + this.gravity;
    // fade out the particle
    this.alpha -= this.decay;

    // remove the particle once the alpha is low enough, based on the passed in index
    if (this.alpha <= this.decay) {
        particles.splice(index, 1);
    }
}

// draw particle
Particle.prototype.draw = function () {
    ctx.beginPath();
    // move to the last tracked coordinates in the set, then draw a line to the current x and y
    ctx.moveTo(this.coordinates[this.coordinates.length - 1][0], this.coordinates[this.coordinates.length - 1][1]);
    ctx.lineTo(this.x, this.y);
    ctx.strokeStyle = 'hsla(' + this.hue + ', 100%, ' + this.brightness + '%, ' + this.alpha + ')';
    ctx.stroke();
}

// create particle group/explosion
function createParticles(x, y) {
    // increase the particle count for a bigger explosion, beware of the canvas performance hit with the increased particles though
    var particleCount = 100;
    while (particleCount--) {
        particles.push(new Particle(x, y));
    }
}

// main demo loop
function loop() {
    // this function will run endlessly with requestAnimationFrame
    requestAnimFrame(loop);

    // increase the hue to get different colored fireworks over time
    hue += 0.5;

    // normally, clearRect() would be used to clear the canvas
    // we want to create a trailing effect though
    // setting the composite operation to destination-out will allow us to clear the canvas at a specific opacity, rather than wiping it entirely
    ctx.globalCompositeOperation = 'destination-out';
    // decrease the alpha property to create more prominent trails
    ctx.fillStyle = 'rgba(0, 0, 0, 0.1)';
    ctx.fillRect(0, 0, cw, ch);
    // change the composite operation back to our main mode
    // lighter creates bright highlight points as the fireworks and particles overlap each other
    ctx.globalCompositeOperation = 'lighter';

    // loop over each firework, draw it, update it
    var i = fireworks.length;
    while (i--) {
        fireworks[i].draw();
        fireworks[i].update(i);
    }

    // loop over each particle, draw it, update it
    var i = particles.length;
    while (i--) {
        particles[i].draw();
        particles[i].update(i);
    }

    // launch fireworks automatically to random coordinates, when the mouse isn't down
    if (timerTick >= timerTotal) {
        if (!mousedown) {
            // start the firework at the bottom middle of the screen, then set the random target coordinates, the random y coordinates will be set within the range of the top half of the screen
            for (var i = 0; i < 3; i++) {
                setTimeout(function () {
                    fireworks.push(new Firework(cw / 2 + random(-cw / 6, cw / 6), ch, random(0, cw), random(0, ch / 2)));
                }, 250 * i);
            }
            timerTick = 0;
        }
    } else {
        timerTick++;
    }

    // limit the rate at which fireworks get launched when mouse is down
    if (limiterTick >= limiterTotal) {
        if (mousedown) {
            // start the firework at the bottom middle of the screen, then set the current mouse coordinates as the target
            fireworks.push(new Firework(cw / 2, ch, mx, my));
            limiterTick = 0;
        }
    } else {
        limiterTick++;
    }
}

// mouse event bindings
// update the mouse coordinates on mousemove
canvas.addEventListener('mousemove', function (e) {
    mx = e.pageX - canvas.offsetLeft;
    my = e.pageY - canvas.offsetTop;
});

// toggle mousedown state and prevent canvas from being selected
canvas.addEventListener('mousedown', function (e) {
    e.preventDefault();
    mousedown = true;
});

canvas.addEventListener('mouseup', function (e) {
    e.preventDefault();
    mousedown = false;
});

loop();

window.onresize = function () {
    cw = canvas.width = window.innerWidth;
    ch = canvas.height = window.innerHeight;
};