diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 00000000..4972eec6
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,37 @@
+GEM
+  remote: http://rubygems.org/
+  specs:
+    childprocess (0.2.2)
+      ffi (~> 1.0.6)
+    diff-lcs (1.1.3)
+    ffi (1.0.9)
+    jasmine (1.1.2)
+      jasmine-core (>= 1.1.0)
+      rack (>= 1.1)
+      rspec (>= 1.3.1)
+      selenium-webdriver (>= 0.1.3)
+    jasmine-core (1.1.0)
+    json_pure (1.6.1)
+    rack (1.3.5)
+    rake (0.9.2.2)
+    rspec (2.7.0)
+      rspec-core (~> 2.7.0)
+      rspec-expectations (~> 2.7.0)
+      rspec-mocks (~> 2.7.0)
+    rspec-core (2.7.1)
+    rspec-expectations (2.7.0)
+      diff-lcs (~> 1.1.2)
+    rspec-mocks (2.7.0)
+    rubyzip (0.9.4)
+    selenium-webdriver (2.10.0)
+      childprocess (>= 0.2.1)
+      ffi (= 1.0.9)
+      json_pure
+      rubyzip
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  jasmine
+  rake
diff --git a/spec/javascripts/helpers/spec_helper.js b/spec/javascripts/helpers/spec_helper.js
index 1f6991d7..7f53fe59 100644
--- a/spec/javascripts/helpers/spec_helper.js
+++ b/spec/javascripts/helpers/spec_helper.js
@@ -1,4 +1,6 @@
 beforeEach(function() {
+  var EPSILON = 0.000001;
+  
   this.addMatchers({
     /*
       Returns true if `actual` has the same length as `expected`, and
@@ -7,9 +9,12 @@ beforeEach(function() {
       of working around floating point imprecision.
     */
     toBeEqualish: function(expected) {
+      if (typeof(this.actual) == 'number')
+        return Math.abs(this.actual) - Math.abs(expected) < EPSILON;
+        
       if (this.actual.length != expected.length) return false;
       for (var i = 0; i < this.actual.length; i++)
-        if (Math.abs(this.actual[i]) - Math.abs(expected[i]) < 0.000001)
+        if (Math.abs(this.actual[i]) - Math.abs(expected[i]) < EPSILON)
           return true;
       return false;
     }
diff --git a/spec/javascripts/vec3_spec.js b/spec/javascripts/vec3_spec.js
index 31f1ffa7..9ce0ceba 100644
--- a/spec/javascripts/vec3_spec.js
+++ b/spec/javascripts/vec3_spec.js
@@ -1,5 +1,5 @@
 describe("vec3", function() {
-  var vec;
+  var vec, vecB, dest;
   
   describe("when Float32Array is not supported", function() {
     beforeEach(function() { setMatrixArrayType(Array); });
@@ -33,4 +33,227 @@ describe("vec3", function() {
       expect(vec[2]).toEqual(3);
     });
   });
+  
+  describe("add", function() {
+    beforeEach(function() { vec = vec3.create([1,2,3]); });
+    
+    it("should modify original vector if dest not given", function() {
+      vec3.add(vec, [3,4,5]);
+      expect(vec).toBeEqualish([4,6,8]);
+    });
+    
+    it("should modify original vector if dest is original vector", function() {
+      vec3.add(vec, [3,4,5], vec);
+      expect(vec).toBeEqualish([4,6,8]);
+    });
+    
+    describe("if dest vector given", function() {
+      beforeEach(function() { vec3.add(vec, [3,4,5], dest = vec3.create()); });
+      
+      it("should not modify original vector", function() {
+        expect(vec).toBeEqualish([3,4,5]);
+      });
+      
+      it("should modify dest vector", function() {
+        expect(dest).toBeEqualish([4,6,8]);
+      });
+    });
+  });
+  
+  describe("subtract", function() {
+    beforeEach(function() { vec = vec3.create([1,2,3]); });
+    
+    it('should modify original vector if dest not given', function() {
+      vec3.subtract(vec, [3, 4, 5]);
+      expect(vec).toBeEqualish([-2,-2,-2]);
+    });
+    
+    it("should modify original vector if dest is original vector", function() {
+      vec3.subtract(vec, [3,4,5], vec);
+      expect(vec).toBeEqualish([-2,-2,-2]);
+    });
+    
+    describe("if dest vector given", function() {
+      beforeEach(function() { vec3.subtract(vec, [3,4,5], dest = vec3.create()); });
+      
+      it("should not modify original vector", function() { expect(vec).toBeEqualish([3,4,5]); });
+      it("should modify dest vector", function() { expect(dest).toBeEqualish([-2,-2,-2]); });
+    });
+  });
+  
+  describe("negate", function() {
+    beforeEach(function() { vec = vec3.create([1,2,3]); });
+    
+    it("should modify original vector if dest not given", function() {
+      vec3.negate(vec);
+      expect(vec).toBeEqualish([-1,-2,-3]);
+    });
+    
+    it("should modify original vector if dest is original vector", function() {
+      vec3.negate(vec, vec);
+      expect(vec).toBeEqualish([-1,-2,-3]);
+    });
+    
+    describe("if dest vector given", function() {
+      beforeEach(function() { vec3.negate(vec, dest = vec3.create()); });
+      
+      it("should not modify original vector", function() { expect(vec).toBeEqualish([1,2,3]); });
+      it("should modify dest vector", function() { expect(dest).toBeEqualish([-1,-2,-3]); });
+    });
+  });
+  
+  describe("scale", function() {
+    beforeEach(function() { vec = vec3.create([1,2,3]); });
+    
+    it("should modify original vector if dest not given", function() {
+      vec3.scale(vec, 2);
+      expect(vec).toBeEqualish([2,4,6]);
+    });
+    
+    it("should modify original vector if dest is original vector", function() {
+      vec3.scale(vec, 2, vec);
+      expect(vec).toBeEqualish([2,4,6]);
+    });
+    
+    describe("if dest vector given", function() {
+      beforeEach(function() { vec3.scale(vec, 2, dest = vec3.create()); });
+      
+      it("should not modify original vector", function() { expect(vec).toBeEqualish([1,2,3]); });
+      it("should modify dest vector", function() { expect(dest).toBeEqualish([2,4,6]); });
+    });
+  });
+  
+  describe("normalize", function() {
+    var NORMAL = [0.267261, 0.534522, 0.801783];
+    beforeEach(function() { vec = vec3.create([1,2,3]); });
+    
+    it("should return [0,0,0] if vector magnitude is 0", function() {
+      expect(vec3.normalize([0,0,0])).toBeEqualish([0,0,0]);
+    });
+    
+    it("should modify original vector if dest not given", function() {
+      vec3.normalize(vec);
+      expect(vec).toBeEqualish(NORMAL);
+    });
+    
+    it("should modify original vector if dest is original vector", function() {
+      vec3.normalize(vec, vec);
+      expect(vec).toBeEqualish(NORMAL);
+    });
+    
+    describe("if dest vector is given", function() {
+      beforeEach(function() { vec3.normalize(vec, dest = vec3.create()); });
+      
+      it("should not modify original vector", function() { expect(vec).toBeEqualish([1,2,3]); });
+      it("should modify dest vector", function() { expect(dest).toBeEqualish(NORMAL); });
+    });
+  });
+  
+  describe("cross", function() {
+    var CROSS = [-3, 6, -3];
+    beforeEach(function() {
+      vec = vec3.create([1,2,3]);
+      vecB = vec3.create([4,5,6]);
+    });
+    
+    it("should modify original vector if dest not given", function() {
+      vec3.cross(vec, vecB);
+      expect(vec).toBeEqualish(CROSS);
+    });
+    
+    it("should not modify vecB", function() {
+      expect(vecB).toBeEqualish([4,5,6]);
+    });
+    
+    it("should modify original mvector if dest is original vector", function() {
+      vec3.cross(vec, vecB, vec);
+      expect(vec).toBeEqualish(CROSS);
+    });
+    
+    describe("if dest vector is given", function() {
+      beforeEach(function() { vec3.cross(vec, vecB, dest = vec3.create()); });
+      
+      it("should not modify original vector", function() { expect(vec).toBeEqualish([1,2,3]); });
+      it("should not modify vecB", function() { expect(vecB).toBeEqualish([4,5,6]); });
+      it("should modify dest vector", function() { expect(dest).toBeEqualish(CROSS); });
+    });
+  });
+  
+  describe("length", function() {
+    beforeEach(function() { vec = vec3.create([1,2,3]); });
+    
+    it("should return vector magnitude", function() { expect(vec3.length(vec)).toBeEqualish(3.741657); });
+  });
+  
+  describe("dot", function() {
+    it("should return dot product", function() { expect(vec3.dot([1,2,3], [-4,5,6])).toBeEqualish(24); });
+  });
+  
+  describe("direction", function() {
+    var DIR = [0.267261, 0.534522, 0.801783];
+    
+    beforeEach(function() {
+      vec = vec3.create([1,2,3]);
+      vecB = vec3.create([-1,-2,-3]);
+    });
+    
+    it("should modify original vector if dest not given", function() {
+      vec3.direction(vec, vecB);
+      expect(vec).toBeEqualish(DIR);
+    });
+    
+    it("should modify original vector if dest is original vector", function() {
+      vec3.direction(vec, vecB, vec);
+      expect(vec).toBeEqualish(DIR);
+    });
+    
+    it("should not modify vecB", function() {
+      vec3.direction(vec, vecB);
+      expect(vecB).toBeEqualish([-1,-2,-3]);
+    });
+    
+    describe("if dest vector is given", function() {
+      beforeEach(function() { vec3.direction(vec, vecB, dest = vec3.create()); });
+      it("should not modify vec", function() { expect(vec).toBeEqualish([1,2,3]); });
+      it("should not modify vecB", function() { expect(vecB).toBeEqualish([-1,-2,-3]); });
+      it("should modify dest", function() { expect(dest).toBeEqualish(DIR); });
+    });
+  });
+  
+  describe("lerp", function() {
+    var amount;
+    var LERP = [2.5, 3.5, 4.5];
+    
+    beforeEach(function() {
+      vec = vec3.create([1,2,3]);
+      vecB = vec3.create([4,5,6]);
+      amount = 0.5;
+    });
+    
+    it("should modify original vector if dest not given", function() {
+      vec3.lerp(vec, vecB, amount);
+      expect(vec).toBeEqualish(LERP);
+    });
+    
+    it("should modify original vector if dest is original vector", function() {
+      vec3.lerp(vec, vecB, amount, vec);
+      expect(vec).toBeEqualish(LERP);
+    });
+    
+    it("should not modify vecB", function() {
+      vec3.lerp(vec, vecB, amount);
+      expect(vecB).toBeEqualish([4,5,6]);
+    });
+    
+    describe("if dest vector is given", function() {
+      beforeEach(function() { vec3.lerp(vec, vecB, amount, dest = vec3.create()); });
+      it("should not modify vec", function() { expect(vec).toBeEqualish([1,2,3]); });
+      it("should not modify vecB", function() { expect(vecB).toBeEqualish([4,5,6]); });
+      it("should modify dest", function() { expect(dest).toBeEqualish(LERP); });
+    });
+  });
+  
+  describe("str", function() {
+    it("should produce pretty string", function() { expect(vec3.str(vec3.create([1,2,3]))).toEqual("[1, 2, 3]"); });
+  });
 });