diff --git a/index.js b/index.js
index d2a0ddb..85fc96e 100644
--- a/index.js
+++ b/index.js
@@ -1,30 +1,58 @@
-'use strict';
-var exec = require('child_process').exec;
-var semverValid = require('semver').valid;
-var regex = /tag:\s*(.+?)[,\)]/gi;
-var cmd = 'git log --decorate --no-color';
-
-module.exports = function(callback) {
-  exec(cmd, {
-    maxBuffer: Infinity
-  }, function(err, data) {
-    if (err) {
-      callback(err);
-      return;
-    }
+var semver = require('semver');
+
+var findIndexByHash = require('./lib/find-index-by-hash');
+var getCommits = require('./lib/get-commits');
+var getSemverTags = require('./lib/get-semver-tags');
+var loadRepository = require('./lib/load-repository');
 
-    var tags = [];
+/**
+ * Get semantic version git tags of repository at process.cwd()
+ *
+ * @param  {MainCallback} callback function to execute after information retrieval
+ */
+function gitSemverTags(callback) {
+  // Initialize repository
+  loadRepository(function(error, repository) {
+    if (error) {
+      return callback(error);
+    }
 
-    data.split('\n').forEach(function(decorations) {
-      var match;
-      while (match = regex.exec(decorations)) {
-        var tag = match[1];
-        if (semverValid(tag)) {
-          tags.push(tag);
-        }
+    // Get a list of commits
+    getCommits(repository, function(error, commits) {
+      /* istanbul ignore if */
+      if (error) {
+        return callback(error);
       }
-    });
 
-    callback(null, tags);
+      // Get a list of tags matching semver pattern
+      var tagNames = getSemverTags(repository)
+        .sort(function(aTag, bTag) {
+          // if tags reference same hash sort descending by semantic version
+          if (aTag.hash === bTag.hash) {
+            return semver.compare(bTag.name, aTag.name);
+          }
+
+          // sort tags descending by occurence in commits list
+          var aCommit = findIndexByHash(commits, aTag.hash);
+          var bCommit = findIndexByHash(commits, bTag.hash);
+          return bCommit - aCommit;
+        })
+        // map out the name
+        .map(function(tag) {
+          return tag.name;
+        });
+
+      return callback(null, tagNames);
+    });
   });
 };
+
+module.exports = gitSemverTags;
+
+/**
+ * Main callback executed after all information has been collected
+ *
+ * @typedef {function} MainCallback
+ * @param {(Error|null)} error - encountered error, if any
+ * @param {array} [tags] - semantic git tags of repository at process.cwd()
+ */
diff --git a/lib/find-index-by-hash.js b/lib/find-index-by-hash.js
new file mode 100644
index 0000000..c85c19c
--- /dev/null
+++ b/lib/find-index-by-hash.js
@@ -0,0 +1,23 @@
+/**
+ * Find index of item with item.hash === hash
+ *
+ * @param {array} commits haystack of commits to search in
+ * @param {string} hash hash to match commits against
+ * @private
+ */
+function findIndexByHash(commits, hash) {
+  // Get first commit matching hash
+  var match = commits.filter(function(commit) {
+    return commit.hash === hash;
+  })[0];
+
+  // No index to find if no match was found
+  if (!match) {
+    return -1;
+  }
+
+  // Return the index of match in haystack
+  return commits.indexOf(match);
+}
+
+module.exports = findIndexByHash;
diff --git a/lib/get-commit-human.js b/lib/get-commit-human.js
new file mode 100644
index 0000000..d08f2f0
--- /dev/null
+++ b/lib/get-commit-human.js
@@ -0,0 +1,28 @@
+var human = require('git-parse-human');
+
+/**
+ * Get human object for commit tagger, author or committer
+ * 
+ * @param {GitCommit} commit
+ * @returns {GitHuman} 
+ * @private
+ */
+function getCommitHuman(commit) {
+	// Use getter for raw information about author of commit, where author is
+	// the tagger, author or committer in said precedence
+	var getter = commit.tagger || commit.author || commit.committer;
+	var bound = getter.bind(commit);
+	// Parse raw author information into commit "human" object
+	return human(bound());
+}
+
+module.exports = getCommitHuman;
+
+/**
+ * @typedef GitHuman
+ * @property {string} name
+ * @property {string} email
+ * @property {number} time unix epoch commit timestamp in milliseconds
+ * @property {number} tzoff time zone offset in milliseconds
+ * @see https://github.com/chrisdickinson/git-parse-human
+ */
diff --git a/lib/get-commit-timestamp.js b/lib/get-commit-timestamp.js
new file mode 100644
index 0000000..9a19f01
--- /dev/null
+++ b/lib/get-commit-timestamp.js
@@ -0,0 +1,17 @@
+var getCommitHuman = require('./get-commit-human');
+
+/**
+ * Get timestamp for commit
+ * 
+ * @param {GitCommit} commit
+ * @returns {number} commit unix epoch timestamp in milliseconds with time zone offset
+ * @private
+ */
+function getCommitTimeStamp(commit) {
+	// get a commiter object from commit object
+	var committer = getCommitHuman(commit);
+	// calculate the time zone offset in
+	return committer.time + committer.tzoff;
+}
+
+module.exports = getCommitTimeStamp;
diff --git a/lib/get-commits.js b/lib/get-commits.js
new file mode 100644
index 0000000..c3c7cfb
--- /dev/null
+++ b/lib/get-commits.js
@@ -0,0 +1,50 @@
+var walk = require('git-walk-refs');
+
+/**
+ * Get commits for repository in reverse chronological order
+ *
+ * @param  {!GitRepository} repository git repository
+ * @param  {!CommitsCallback} callback function to execute after information retrieval
+ * @private
+ */
+function getCommits(repository, callback) {
+  var commits = []; // results array
+
+  // Get an array of refs
+  var head = repository.refs().map(function(ref) {
+    return ref.hash;
+  });
+
+  // Walk the git history for each ref
+  walk(repository.find, head)
+    .on('error', callback)
+    .on('end', function() {
+      // return list in inverse chronological order
+      return callback(null, commits.reverse());
+    })
+    .on('data', function(data) {
+      // add commit entry to results array
+      commits.push({
+        hash: data.hash,
+        message: data.message()
+      });
+    });
+}
+
+module.exports = getCommits;
+/**
+ * @callback CommitsCallback
+ * @param {?Error} error error encountered if any
+ * @param {GitCommit[]} [commits] commits in inverse chronological order
+ * @private
+ */
+
+/**
+ * @typedef GitCommit
+ * @property {function?} author
+ * @property {function?} committer
+ * @property {function?} tagger
+ * @property {!string} hash
+ * @see https://github.com/chrisdickinson/git-walk-refs
+ * @private
+ */
diff --git a/lib/get-semver-tags.js b/lib/get-semver-tags.js
new file mode 100644
index 0000000..44c6e36
--- /dev/null
+++ b/lib/get-semver-tags.js
@@ -0,0 +1,21 @@
+var semver = require('semver');
+var getTags = require('./get-tags');
+
+/**
+ * Get git tags of repository matching semantic version pattern
+ * 
+ * @param {GitRepository} repository
+ * @returns {GitTag[]}
+ * @see https://github.com/npm/node-semver#functions
+ * @private
+ */
+function getSemverTags(repository) {
+	// Get all tags
+	return getTags(repository)
+		// Filter for valid semver tags
+		.filter(function(tag) {
+			return semver.valid(tag.name);
+		});
+}
+
+module.exports = getSemverTags;
diff --git a/lib/get-tags.js b/lib/get-tags.js
new file mode 100644
index 0000000..83bb26f
--- /dev/null
+++ b/lib/get-tags.js
@@ -0,0 +1,31 @@
+/**
+ * Get tags for repository
+ * 
+ * @param {!GitRepository} repository
+ * @returns {GitTag[]} 
+ * @private
+ */
+function getTags(repository) {
+	// Get all references
+	return repository.refs(false)
+		// Filter for references matching git tag ref paths
+		.filter(function(ref){
+			return ref.name.indexOf('refs/tags/') === 0;
+		})
+		// Pick relevant information
+		.map(function(tag){
+			return {
+				name: tag.name.replace(/^refs\/tags\//, ''),
+				hash: tag.hash
+			};
+		});
+}
+
+module.exports = getTags;
+
+/**
+ * @typedef GitTag
+ * @property name git tag name
+ * @property hash git hash referenced by this tag
+ * @private
+ */
diff --git a/lib/load-repository.js b/lib/load-repository.js
new file mode 100644
index 0000000..5a4a909
--- /dev/null
+++ b/lib/load-repository.js
@@ -0,0 +1,51 @@
+var path = require('path');
+var gitFsRepo = require('git-fs-repo');
+
+/**
+ * Initialize a git repository
+ *
+ * @param  {RepositoryCallback} callback
+ * @private
+ */
+function loadRepository(callback) {
+	// Use $cwd/.git as git database directory
+	var gitDirectory = path.join(process.cwd(), '.git');
+
+	// Initialize a js-backed representation of the local git repository
+	gitFsRepo(gitDirectory, function(error, gitRepository) {
+		/* istanbul ignore if */
+		if (error) {
+			return callback(error);
+		}
+
+		// get the current head object
+		var head = gitRepository.ref('HEAD');
+
+		// if there is no head object this repository most likely has no commits
+		if (!head) {
+			var headErrors = new Error('Git repository has no HEAD, are there any commits?');
+			return callback(headErrors);
+		}
+
+		callback(null, gitRepository);
+	});
+}
+
+module.exports = loadRepository;
+
+/**
+ * @typedef {Object} GitRepository
+ * @property {function} ref
+ * @property {function} refs
+ * @see https://github.com/chrisdickinson/git-fs-repo
+ * @private
+ */
+
+/**
+ * Main callback executed after all information has been collected
+ *
+ * @callback RepositoryCallback
+ * @param {(Error|null)} error - encountered error, if any
+ * @param {GitRepositpry} [gitRepository]
+ * @private
+ */
diff --git a/package.json b/package.json
index 3000d47..c775521 100644
--- a/package.json
+++ b/package.json
@@ -11,6 +11,7 @@
   "repository": "stevemao/git-semver-tags",
   "license": "MIT",
   "files": [
+    "lib",
     "index.js",
     "cli.js"
   ],
@@ -23,6 +24,10 @@
     "git"
   ],
   "dependencies": {
+    "async": "^2.0.0-rc.5",
+    "git-fs-repo": "0.0.5",
+    "git-parse-human": "0.0.1",
+    "git-walk-refs": "0.0.2",
     "meow": "^3.3.0",
     "semver": "^5.0.1"
   },
@@ -37,7 +42,7 @@
   },
   "scripts": {
     "coverage": "istanbul cover _mocha -- -R spec && rm -rf ./coverage",
-    "lint": "jshint *.js --exclude node_modules && jscs *.js",
+    "lint": "jshint **/*.js --exclude node_modules && jscs *.js",
     "test": "npm run-script lint && mocha --timeout 10000"
   },
   "bin": {
diff --git a/test.js b/test.js
index 8aa2d63..acfb18a 100644
--- a/test.js
+++ b/test.js
@@ -1,6 +1,7 @@
 'use strict';
 var assert = require('assert');
 var equal = assert.deepEqual;
+var findIndexByHash = require('./lib/find-index-by-hash');
 var gitSemverTags = require('./');
 var shell = require('shelljs');
 var writeFileSync = require('fs').writeFileSync;
@@ -12,104 +13,125 @@ shell.mkdir('tmp');
 shell.cd('tmp');
 shell.exec('git init');
 
-it('should error if no commits found', function(done) {
-  gitSemverTags(function(err) {
-    assert(err);
+describe('find-index-by-hash', function() {
+  it('should return -1 for an empty array', function() {
+    var actual = findIndexByHash([], null);
+    var expected = -1;
 
-    done();
+    equal(actual, expected);
+  });
+
+  it('should return the first match index', function() {
+    var actual = findIndexByHash([
+      {hash: 1},
+      {hash: 1}
+    ], 1);
+    var expected = 0;
+
+    equal(actual, expected);
   });
 });
 
-it('should get no semver tags', function(done) {
-  writeFileSync('test1', '');
-  shell.exec('git add --all && git commit -m"First commit"');
-  shell.exec('git tag foo');
+describe('git-semver-tags', function() {
+  it('should error if no commits found', function(done) {
+    gitSemverTags(function(err) {
+      assert(err);
 
-  gitSemverTags(function(err, tags) {
-    equal(tags, []);
+      done();
+    });
+  });
 
-    done();
+  it('should get no semver tags', function(done) {
+    writeFileSync('test1', '');
+    shell.exec('git add --all && git commit -m"First commit"');
+    shell.exec('git tag foo');
+
+    gitSemverTags(function(err, tags) {
+      equal(tags, []);
+
+      done();
+    });
   });
-});
 
-it('should get the semver tag', function(done) {
-  writeFileSync('test2', '');
-  shell.exec('git add --all && git commit -m"Second commit"');
-  shell.exec('git tag v2.0.0');
-  writeFileSync('test3', '');
-  shell.exec('git add --all && git commit -m"Third commit"');
-  shell.exec('git tag va.b.c');
+  it('should get the semver tag', function(done) {
+    writeFileSync('test2', '');
+    shell.exec('git add --all && git commit -m"Second commit"');
+    shell.exec('git tag v2.0.0');
+    writeFileSync('test3', '');
+    shell.exec('git add --all && git commit -m"Third commit"');
+    shell.exec('git tag va.b.c');
 
-  gitSemverTags(function(err, tags) {
-    equal(tags, ['v2.0.0']);
+    gitSemverTags(function(err, tags) {
+      equal(tags, ['v2.0.0']);
 
-    done();
+      done();
+    });
   });
-});
 
-it('should get both semver tags', function(done) {
-  shell.exec('git tag v3.0.0');
+  it('should get both semver tags', function(done) {
+    shell.exec('git tag v3.0.0');
 
-  gitSemverTags(function(err, tags) {
-    equal(tags, ['v3.0.0', 'v2.0.0']);
+    gitSemverTags(function(err, tags) {
+      equal(tags, ['v3.0.0', 'v2.0.0']);
 
-    done();
+      done();
+    });
   });
-});
 
-it('should get all semver tags if two tags on the same commit', function(done) {
-  shell.exec('git tag v4.0.0');
+  it('should get all semver tags if two tags on the same commit', function(done) {
+    shell.exec('git tag v4.0.0');
 
-  gitSemverTags(function(err, tags) {
-    equal(tags, ['v4.0.0', 'v3.0.0', 'v2.0.0']);
+    gitSemverTags(function(err, tags) {
+      equal(tags, ['v4.0.0', 'v3.0.0', 'v2.0.0']);
 
-    done();
+      done();
+    });
   });
-});
 
-it('should still work if I run it again', function(done) {
-  gitSemverTags(function(err, tags) {
-    equal(tags, ['v4.0.0', 'v3.0.0', 'v2.0.0']);
+  it('should still work if I run it again', function(done) {
+    gitSemverTags(function(err, tags) {
+      equal(tags, ['v4.0.0', 'v3.0.0', 'v2.0.0']);
 
-    done();
+      done();
+    });
   });
-});
 
-it('should be in reverse chronological order', function(done) {
-  writeFileSync('test4', '');
-  shell.exec('git add --all && git commit -m"Fourth commit"');
-  shell.exec('git tag v1.0.0');
+  it('should be in reverse chronological order', function(done) {
+    writeFileSync('test4', '');
+    shell.exec('git add --all && git commit -m"Fourth commit"');
+    shell.exec('git tag v1.0.0');
 
-  gitSemverTags(function(err, tags) {
-    equal(tags, ['v1.0.0', 'v4.0.0', 'v3.0.0', 'v2.0.0']);
+    gitSemverTags(function(err, tags) {
+      equal(tags, ['v1.0.0', 'v4.0.0', 'v3.0.0', 'v2.0.0']);
 
-    done();
+      done();
+    });
   });
-});
 
-it('should work with prerelease', function(done) {
-  writeFileSync('test5', '');
-  shell.exec('git add --all && git commit -m"Fifth commit"');
-  shell.exec('git tag 5.0.0-pre');
+  it('should work with prerelease', function(done) {
+    writeFileSync('test5', '');
+    shell.exec('git add --all && git commit -m"Fifth commit"');
+    shell.exec('git tag 5.0.0-pre');
 
-  gitSemverTags(function(err, tags) {
-    equal(tags, ['5.0.0-pre', 'v1.0.0', 'v4.0.0', 'v3.0.0', 'v2.0.0']);
+    gitSemverTags(function(err, tags) {
+      equal(tags, ['5.0.0-pre', 'v1.0.0', 'v4.0.0', 'v3.0.0', 'v2.0.0']);
 
-    done();
+      done();
+    });
   });
-});
 
-it('should work with empty commit', function(done) {
-  shell.rm('-rf', '.git');
-  shell.exec('git init');
-  gitDummyCommit('empty commit');
-  shell.exec('git tag v1.1.0');
-  gitDummyCommit('empty commit2');
-  gitDummyCommit('empty commit3');
+  it('should work with empty commit', function(done) {
+    shell.rm('-rf', '.git');
+    shell.exec('git init');
+    gitDummyCommit('empty commit');
+    shell.exec('git tag v1.1.0');
+    gitDummyCommit('empty commit2');
+    gitDummyCommit('empty commit3');
 
-  gitSemverTags(function(err, tags) {
-    equal(tags, ['v1.1.0']);
+    gitSemverTags(function(err, tags) {
+      equal(tags, ['v1.1.0']);
 
-    done();
+      done();
+    });
   });
 });