diff --git a/compiler/index.js b/compiler/index.js
index 29e47fcd3..17f642ee7 100644
--- a/compiler/index.js
+++ b/compiler/index.js
@@ -127,13 +127,16 @@ exports.createWalker = createWalker;
 exports.builder = Builder.DEFAULT_BUILDER;
 
 var taglibLookup = require('./taglib-lookup');
+exports.taglibLookup = taglibLookup;
+exports.taglibLoader = require('./taglib-loader');
+
 taglibLookup.registerTaglib(require.resolve('../taglibs/core/marko-taglib.json'));
 taglibLookup.registerTaglib(require.resolve('../taglibs/layout/marko-taglib.json'));
 taglibLookup.registerTaglib(require.resolve('../taglibs/html/marko-taglib.json'));
 
 /*
 exports.Taglib = require('./Taglib');
-exports.loader = require('./taglib-loader');
+
 exports.lookup = require('./taglib-lookup');
 exports.buildLookup = exports.lookup.buildLookup;
 exports.registerTaglib = exports.lookup.registerTaglib;
diff --git a/compiler/taglib-lookup/index.js b/compiler/taglib-lookup/index.js
index 12a5c77a8..2cc74642f 100644
--- a/compiler/taglib-lookup/index.js
+++ b/compiler/taglib-lookup/index.js
@@ -14,6 +14,9 @@
 * limitations under the License.
 */
 'use strict';
+exports.registerTaglib = registerTaglib;
+exports.buildLookup = buildLookup;
+exports.clearCaches = clearCaches;
 
 var taglibLoader = require('../taglib-loader');
 var taglibFinder = require('../taglib-finder');
@@ -74,9 +77,4 @@ function registerTaglib(taglib) {
 
 function clearCaches() {
 	lookupCache = {};
-}
-
-exports.excludeDir = taglibFinder.excludeDir;
-exports.registerTaglib = registerTaglib;
-exports.buildLookup = buildLookup;
-exports.clearCaches = clearCaches;
\ No newline at end of file
+}
\ No newline at end of file
diff --git a/taglibs/core/marko-taglib.json b/taglibs/core/marko-taglib.json
index 6558f4cbe..b2904d01b 100644
--- a/taglibs/core/marko-taglib.json
+++ b/taglibs/core/marko-taglib.json
@@ -47,6 +47,9 @@
         "@else-if": "argument",
         "@else": "argument",
         "@for": "argument",
-        "transformer": "./core-transformer"
+        "transformer": {
+            "path": "./core-transformer",
+            "priority": 0
+        }
     }
 }
\ No newline at end of file
diff --git a/test/fixtures/taglib-custom-attribute/marko-taglib.json b/test/fixtures/taglib-custom-attribute/marko-taglib.json
new file mode 100644
index 000000000..9acdd3ce6
--- /dev/null
+++ b/test/fixtures/taglib-custom-attribute/marko-taglib.json
@@ -0,0 +1,5 @@
+{
+    "<*>": {
+        "@global-attribute": "boolean"
+    }
+}
\ No newline at end of file
diff --git a/test/fixtures/taglib-duplicate/foo-renderer.js b/test/fixtures/taglib-duplicate/foo-renderer.js
new file mode 100644
index 000000000..ddb02a748
--- /dev/null
+++ b/test/fixtures/taglib-duplicate/foo-renderer.js
@@ -0,0 +1,3 @@
+exports.render = function(input, out) {
+
+};
\ No newline at end of file
diff --git a/test/fixtures/taglib-duplicate/marko-taglib.json b/test/fixtures/taglib-duplicate/marko-taglib.json
new file mode 100644
index 000000000..abe89e11c
--- /dev/null
+++ b/test/fixtures/taglib-duplicate/marko-taglib.json
@@ -0,0 +1,6 @@
+{
+    "taglib-id": "taglib-duplicate",
+    "<duplicate-foo>": {
+        "renderer": "./foo-renderer.js"
+    }
+}
\ No newline at end of file
diff --git a/test/fixtures/taglib-duplicate/taglib-duplicate/bar-renderer.js b/test/fixtures/taglib-duplicate/taglib-duplicate/bar-renderer.js
new file mode 100644
index 000000000..ddb02a748
--- /dev/null
+++ b/test/fixtures/taglib-duplicate/taglib-duplicate/bar-renderer.js
@@ -0,0 +1,3 @@
+exports.render = function(input, out) {
+
+};
\ No newline at end of file
diff --git a/test/fixtures/taglib-duplicate/taglib-duplicate/marko-taglib.json b/test/fixtures/taglib-duplicate/taglib-duplicate/marko-taglib.json
new file mode 100644
index 000000000..b9bd03fdf
--- /dev/null
+++ b/test/fixtures/taglib-duplicate/taglib-duplicate/marko-taglib.json
@@ -0,0 +1,6 @@
+{
+    "taglib-id": "taglib-duplicate",
+    "<duplicate-bar>": {
+        "renderer": "./bar-renderer.js"
+    }
+}
\ No newline at end of file
diff --git a/test/fixtures/taglib-dynamic-attribute/marko-taglib.json b/test/fixtures/taglib-dynamic-attribute/marko-taglib.json
new file mode 100644
index 000000000..5a1c3270f
--- /dev/null
+++ b/test/fixtures/taglib-dynamic-attribute/marko-taglib.json
@@ -0,0 +1,7 @@
+{
+    "<test-dynamic-attribute>": {
+        "renderer": "./renderer.js",
+        "@foo": "string",
+        "@*": "boolean"
+    }
+}
\ No newline at end of file
diff --git a/test/fixtures/taglib-dynamic-attribute/renderer.js b/test/fixtures/taglib-dynamic-attribute/renderer.js
new file mode 100644
index 000000000..c3b42bc5b
--- /dev/null
+++ b/test/fixtures/taglib-dynamic-attribute/renderer.js
@@ -0,0 +1 @@
+module.exports = function() {};
\ No newline at end of file
diff --git a/test/fixtures/taglib-nested/foo-renderer.js b/test/fixtures/taglib-nested/foo-renderer.js
new file mode 100644
index 000000000..7ba89a90b
--- /dev/null
+++ b/test/fixtures/taglib-nested/foo-renderer.js
@@ -0,0 +1,3 @@
+exports.render = function(input, out) {
+	out.write('nested/a');
+};
\ No newline at end of file
diff --git a/test/fixtures/taglib-nested/marko-taglib.json b/test/fixtures/taglib-nested/marko-taglib.json
new file mode 100644
index 000000000..db511eda3
--- /dev/null
+++ b/test/fixtures/taglib-nested/marko-taglib.json
@@ -0,0 +1,10 @@
+{
+    "tags": {
+        "nested-foo": {
+            "renderer": "./foo-renderer.js",
+            "attributes": {
+                "attr1": "string"
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/test/fixtures/taglib-shorthand/marko-taglib.json b/test/fixtures/taglib-shorthand/marko-taglib.json
new file mode 100644
index 000000000..9fc49894f
--- /dev/null
+++ b/test/fixtures/taglib-shorthand/marko-taglib.json
@@ -0,0 +1,25 @@
+{
+    "<shorthand-checkbox>": {
+        "@label <label>": "string",
+        "@checked": "boolean",
+        "<checked>": "boolean"
+    },
+    "<shorthand-overlay>": {
+        "nested-tags": {
+            "body": {
+                "@condensed": "boolean"
+            }
+        }
+    },
+    "tags": {
+        "shorthand-button": {
+            "@label": "string"
+        },
+        "shorthand-tabs": {
+            "@tabs <tab>[]": {
+                "@label": "string"
+            },
+            "@orientation": "string"
+        }
+    }
+}
\ No newline at end of file
diff --git a/test/fixtures/taglib-transformers/bar-transformer.js b/test/fixtures/taglib-transformers/bar-transformer.js
new file mode 100644
index 000000000..5dc633784
--- /dev/null
+++ b/test/fixtures/taglib-transformers/bar-transformer.js
@@ -0,0 +1,3 @@
+exports.transform = function (node, compiler, template) {
+
+};
\ No newline at end of file
diff --git a/test/fixtures/taglib-transformers/foo-transformer.js b/test/fixtures/taglib-transformers/foo-transformer.js
new file mode 100644
index 000000000..5dc633784
--- /dev/null
+++ b/test/fixtures/taglib-transformers/foo-transformer.js
@@ -0,0 +1,3 @@
+exports.transform = function (node, compiler, template) {
+
+};
\ No newline at end of file
diff --git a/test/fixtures/taglib-transformers/marko-taglib.json b/test/fixtures/taglib-transformers/marko-taglib.json
new file mode 100644
index 000000000..ef22aeb20
--- /dev/null
+++ b/test/fixtures/taglib-transformers/marko-taglib.json
@@ -0,0 +1,18 @@
+{
+    "tags": {
+        "transform-foo": {
+            "transformer": {
+                "name": "foo",
+                "path": "./foo-transformer.js",
+                "priority": -1
+            }
+        },
+        "transform-bar": {
+            "transformer": {
+                "name": "bar",
+                "path": "./bar-transformer.js",
+                "priority": 1
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/test/taglib-loader-test.js b/test/taglib-loader-test.js
index bba89fd33..3bf3c24d5 100644
--- a/test/taglib-loader-test.js
+++ b/test/taglib-loader-test.js
@@ -5,7 +5,7 @@ require('chai').should();
 var expect = require('chai').expect;
 var nodePath = require('path');
 
-xdescribe('taglib-loader' , function() {
+describe('taglib-loader' , function() {
 
     beforeEach(function(done) {
         for (var k in require.cache) {
@@ -18,7 +18,7 @@ xdescribe('taglib-loader' , function() {
     });
 
     it('should load a taglib with shorthand attributes and tags', function() {
-        var taglibLoader = require('../compiler/taglibs').loader;
+        var taglibLoader = require('../compiler').taglibLoader;
         var taglib = taglibLoader.load(nodePath.join(__dirname, 'fixtures/taglib-shorthand/marko-taglib.json'));
         expect(taglib != null).to.equal(true);
 
diff --git a/test/taglib-lookup-test.js b/test/taglib-lookup-test.js
index be2d8d123..dd696b82d 100644
--- a/test/taglib-lookup-test.js
+++ b/test/taglib-lookup-test.js
@@ -5,7 +5,7 @@ require('chai').should();
 var expect = require('chai').expect;
 var nodePath = require('path');
 
-xdescribe('taglib-lookup' , function() {
+describe('taglib-lookup' , function() {
 
     beforeEach(function(done) {
         for (var k in require.cache) {
@@ -18,33 +18,24 @@ xdescribe('taglib-lookup' , function() {
     });
 
     it('should lookup core attributes for top-level template', function() {
-        var taglibLookup = require('../compiler/taglib-lookup');
+        var taglibLookup = require('../compiler').taglibLookup;
         var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures'));
         // console.log('LOOKUP: ', Object.keys(lookup.attributes));
         var ifAttr = lookup.getAttribute('div', 'if');
         expect(ifAttr != null).to.equal(true);
-        expect(ifAttr.type).to.equal('expression');
+        expect(ifAttr.type).to.equal('argument');
     });
 
     it('should lookup core tag for top-level template', function() {
-        var taglibLookup = require('../compiler/taglib-lookup');
+        var taglibLookup = require('../compiler').taglibLookup;
         var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures'));
         var ifTag = lookup.getTag('if');
         expect(ifTag != null).to.equal(true);
         expect(ifTag.name).to.equal('if');
     });
 
-    it('should lookup core template for top-level template', function() {
-        var taglibLookup = require('../compiler/taglib-lookup');
-        var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures'));
-        // console.log(Object.keys(lookup.tags));
-        var templateTag = lookup.getTag('c-template');
-        expect(templateTag != null).to.equal(true);
-        expect(templateTag.name).to.equal('c-template');
-    });
-
     it('should lookup custom tag for top-level template', function() {
-        var taglibLookup = require('../compiler/taglib-lookup');
+        var taglibLookup = require('../compiler').taglibLookup;
         var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures'));
         var tag = lookup.getTag('test-hello');
         // console.log(Object.keys(lookup.tags));
@@ -52,35 +43,23 @@ xdescribe('taglib-lookup' , function() {
         expect(tag.name).to.equal('test-hello');
     });
 
-    it('should lookup custom attributes for top-level template', function() {
-        var taglibLookup = require('../compiler/taglib-lookup');
-        var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures'));
+    it('should allow for declared and dynamic attributes', function() {
+        var taglibLookup = require('../compiler').taglibLookup;
+        var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures/taglib-dynamic-attribute'));
         // console.log(Object.keys(lookup.attributes));
-        var attr = lookup.getAttribute('test-hello', 'name');
+        var attr = lookup.getAttribute('test-dynamic-attribute', 'DYNAMIC');
+        expect(attr != null).to.equal(true);
+        expect(attr.type).to.equal('boolean');
+        expect(attr.name).to.equal('*');
+
+        attr = lookup.getAttribute('test-dynamic-attribute', 'foo');
         expect(attr != null).to.equal(true);
         expect(attr.type).to.equal('string');
-
-        var attr2 = lookup.getAttribute('test-hello', 'splat');
-        expect(attr2 != null).to.equal(true);
-        expect(attr2.type).to.equal('number');
-
-        attr = lookup.getAttribute('test-hello', 'expr');
-        expect(attr != null).to.equal(true);
-        expect(attr.type).to.equal('expression');
-    });
-
-    it('should allow for dynamic attributes', function() {
-        var taglibLookup = require('../compiler/taglib-lookup');
-        var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures'));
-        // console.log(Object.keys(lookup.attributes));
-        var attr = lookup.getAttribute('test-hello', 'DYNAMIC');
-        expect(attr != null).to.equal(true);
-        expect(attr.type).to.equal('number');
     });
 
     it('should lookup global attributes correctly', function() {
-        var taglibLookup = require('../compiler/taglib-lookup');
-        var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures'));
+        var taglibLookup = require('../compiler').taglibLookup;
+        var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures/taglib-custom-attribute'));
         // console.log('LOOKUP: ', Object.keys(lookup.attributes));
         var attrDef = lookup.getAttribute('test-dynamic-attributes', 'global-attribute');
         expect(attrDef != null).to.equal(true);
@@ -88,7 +67,7 @@ xdescribe('taglib-lookup' , function() {
     });
 
     it('should cache a lookup', function() {
-        var taglibLookup = require('../compiler/taglib-lookup');
+        var taglibLookup = require('../compiler').taglibLookup;
         var lookup1 = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures'));
         var lookup2 = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures'));
         var lookup3 = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures/taglib-empty'));
@@ -99,7 +78,7 @@ xdescribe('taglib-lookup' , function() {
     });
 
     it('should lookup nested tags', function() {
-        var taglibLookup = require('../compiler/taglib-lookup');
+        var taglibLookup = require('../compiler').taglibLookup;
         var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures/taglib-nested'));
         var tag = lookup.getTag('nested-foo');
 
@@ -108,7 +87,7 @@ xdescribe('taglib-lookup' , function() {
     });
 
     it('should lookup attributes for nested tags', function() {
-        var taglibLookup = require('../compiler/taglib-lookup');
+        var taglibLookup = require('../compiler').taglibLookup;
         var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures/taglib-nested'));
         // console.log(Object.keys(lookup.attributes));
         var attr = lookup.getAttribute('nested-foo', 'attr1');
@@ -119,20 +98,20 @@ xdescribe('taglib-lookup' , function() {
     it('should lookup tag transformers correctly for un-namespaced tags', function() {
         var transformers = [];
 
-        var taglibLookup = require('../compiler/taglib-lookup');
+        var taglibLookup = require('../compiler').taglibLookup;
         var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures/taglib-nested'));
 
         lookup.forEachTagTransformer('div', function(transformer) {
             transformers.push(transformer);
         });
 
-        expect(transformers.length).to.equal(2);
+        expect(transformers.length).to.equal(1);
     });
 
     it('should lookup tag transformers correctly for namespaced tag with transformer', function() {
         var transformers;
 
-        var taglibLookup = require('../compiler/taglib-lookup');
+        var taglibLookup = require('../compiler').taglibLookup;
         var lookup;
         // lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures/nested'));
 
@@ -150,40 +129,36 @@ xdescribe('taglib-lookup' , function() {
             transformers.push(transformer);
         });
 
-        expect(transformers.length).to.equal(3);
+        expect(transformers.length).to.equal(2);
         expect(transformers[0].path.indexOf('foo')).to.not.equal(-1);
-        expect(transformers[1].path.indexOf('core-tag-transformer')).to.not.equal(-1);
-        expect(transformers[2].path.indexOf('html-tag-transformer')).to.not.equal(-1);
+        expect(transformers[1].path.indexOf('core-transformer')).to.not.equal(-1);
 
         transformers = [];
         lookup.forEachTagTransformer('transform-bar', function(transformer) {
             transformers.push(transformer);
         });
 
-        expect(transformers.length).to.equal(3);
-        expect(transformers[0].path.indexOf('core-tag-transformer')).to.not.equal(-1);
+        expect(transformers.length).to.equal(2);
+        expect(transformers[0].path.indexOf('core-transformer')).to.not.equal(-1);
         expect(transformers[1].path.indexOf('bar')).to.not.equal(-1);
-        expect(transformers[2].path.indexOf('html-tag-transformer')).to.not.equal(-1);
     });
 
     it('should lookup tag transformers core tag with custom node', function() {
         var transformers = [];
 
-        var taglibLookup = require('../compiler/taglib-lookup');
+        var taglibLookup = require('../compiler').taglibLookup;
         var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures/taglib-nested'));
 
         lookup.forEachTagTransformer('else', function(transformer) {
             transformers.push(transformer);
         });
 
-        expect(transformers.length).to.equal(3);
-        expect(transformers[0].path.indexOf('core-tag-transformer')).to.not.equal(-1);
-        expect(transformers[1].path.indexOf('else-tag-transformer')).to.not.equal(-1);
-        expect(transformers[2].path.indexOf('html-tag-transformer')).to.not.equal(-1);
+        expect(transformers.length).to.equal(1);
+        expect(transformers[0].path.indexOf('core-transformer')).to.not.equal(-1);
     });
 
     it('should de-duplicate taglibs', function() {
-        var taglibLookup = require('../compiler/taglib-lookup');
+        var taglibLookup = require('../compiler').taglibLookup;
         var lookup = taglibLookup.buildLookup(nodePath.join(__dirname, 'fixtures/taglib-duplicate/taglib-duplicate'));
 
         // The "duplicate-bar" tag was declared in the lower