diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..54681b3
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,11 @@
+language: python
+python:
+  - "2.6"
+  - "2.7"
+  - "3.3"
+  - "3.4"
+  - "3.5"
+  - "pypy"
+
+install: "pip install -e .[test]"
+script: py.test
diff --git a/examples/app1.py b/examples/app1.py
index 74afeac..f61e14f 100644
--- a/examples/app1.py
+++ b/examples/app1.py
@@ -7,7 +7,7 @@
 
 from werkzeug.wrappers import Request, Response
 
-from katla.renderer import HTML5Renderer
+from katla.renderer import HTMLRenderer
 
 from app1_root import Root
 
@@ -18,7 +18,7 @@ def __init__(self):
         self.root = Root()
 
     def dispatch_request(self, request):
-        res = HTML5Renderer().render(self.root)
+        res = HTMLRenderer().render(self.root)
         return Response(res.to_html_string(), mimetype='text/html')
 
     def wsgi_app(self, environ, start_response):
diff --git a/katla/renderer.py b/katla/renderer.py
index a3f8c81..eab8fe4 100644
--- a/katla/renderer.py
+++ b/katla/renderer.py
@@ -7,7 +7,7 @@
 
 from lxml import etree
 
-from . import attributes
+from . import transforms
 from .tag import tag
 
 
@@ -25,8 +25,8 @@ def to_html_string(self):
                               doctype=None)
 
 
-base_attributes = {'style': attributes.style,
-                   'className' : attributes.className}
+base_transforms = {'style': transforms.style,
+                   'className' : transforms.className}
 
 
 class BaseRenderer(object):
@@ -37,8 +37,140 @@ def render(self, comp):
         return RenderedTree(tree)
 
 
-class HTML5Renderer(BaseRenderer):
+class HTMLRenderer(BaseRenderer):
 
-    # div = partial(etree.Element, 'div')
-    span = tag('span', base_attributes)
-    div = tag('div', base_attributes)
+    # From list @ https://developer.mozilla.org/fr/docs/Web/HTML/Element
+
+    html = tag('html')
+
+    # Meta
+    base = tag('base', base_transforms)
+    head = tag('head', base_transforms)
+    link = tag('link', base_transforms)
+    meta = tag('meta', base_transforms)
+    style = tag('style', base_transforms)
+    title = tag('title', base_transforms)
+
+    # Content
+    address = tag('address', base_transforms)
+    article = tag('article', base_transforms)
+    body = tag('body', base_transforms)
+    footer = tag('footer', base_transforms)
+    header = tag('header', base_transforms)
+    h1 = tag('h1', base_transforms)
+    h2 = tag('h2', base_transforms)
+    h3 = tag('h3', base_transforms)
+    h4 = tag('h4', base_transforms)
+    h5 = tag('h5', base_transforms)
+    h6 = tag('h6', base_transforms)
+    hgroup = tag('hgroup', base_transforms)
+    nav = tag('nav', base_transforms)
+    section = tag('section', base_transforms)
+
+    # Text content
+    blockquote = tag('blockquote', base_transforms)
+    dd = tag('dd', base_transforms)
+    div = tag('div', base_transforms)
+    dl = tag('dl', base_transforms)
+    dt = tag('dt', base_transforms)
+    figcaption = tag('figcaption', base_transforms)
+    figure = tag('figure', base_transforms)
+    hr = tag('hr', base_transforms)
+    li = tag('li', base_transforms)
+    main = tag('main', base_transforms)
+    ol = tag('ol', base_transforms)
+    p = tag('p', base_transforms)
+    pre = tag('pre', base_transforms)
+    ul = tag('ul', base_transforms)
+
+    # Text semantics
+    a = tag('a', base_transforms)
+    abbr = tag('abbr', base_transforms)
+    b = tag('b', base_transforms)
+    bdi = tag('bdi', base_transforms)
+    bdo = tag('bdo', base_transforms)
+    br = tag('br', base_transforms)
+    cite = tag('cite', base_transforms)
+    code = tag('code', base_transforms)
+    data = tag('data', base_transforms)
+    dfn = tag('dfn', base_transforms)
+    em = tag('em', base_transforms)
+    i = tag('i', base_transforms)
+    kbd = tag('kbd', base_transforms)
+    mark = tag('mark', base_transforms)
+    q = tag('q', base_transforms)
+    rp = tag('rp', base_transforms)
+    rt = tag('rt', base_transforms)
+    ruby = tag('ruby', base_transforms)
+    s = tag('s', base_transforms)
+    samp = tag('samp', base_transforms)
+    small = tag('small', base_transforms)
+    span = tag('span', base_transforms)
+    strong = tag('strong', base_transforms)
+    sub = tag('sub', base_transforms)
+    sup = tag('sup', base_transforms)
+    time = tag('time', base_transforms)
+    u = tag('u', base_transforms)
+    var = tag('var', base_transforms)
+    wbr = tag('wbr', base_transforms)
+
+    # Image and multimedia
+    area = tag('area', base_transforms)
+    audio = tag('audio', base_transforms)
+    img = tag('img', base_transforms)
+    map_ = tag('map', base_transforms)
+    track = tag('track', base_transforms)
+    video = tag('video', base_transforms)
+
+    # Embedded content
+    embed = tag('embed', base_transforms)
+    iframe = tag('iframe', base_transforms)
+    object = tag('object', base_transforms)
+    param = tag('param', base_transforms)
+    source = tag('source', base_transforms)
+
+    # Scripts
+    canvas = tag('canvas', base_transforms)
+    script = tag('script', base_transforms)
+    noscript = tag('noscript', base_transforms)
+
+    # Edition
+    del_ = tag('del', base_transforms)
+    ins = tag('ins', base_transforms)
+
+    # Tables
+    caption = tag('caption', base_transforms)
+    col = tag('col', base_transforms)
+    colgroup = tag('colgroup', base_transforms)
+    table = tag('table', base_transforms)
+    tbody = tag('tbody', base_transforms)
+    td = tag('td', base_transforms)
+    tfoot = tag('tfoot', base_transforms)
+    th = tag('th', base_transforms)
+    thead = tag('thead', base_transforms)
+    tr = tag('tr', base_transforms)
+
+    # Forms
+    button = tag('button', base_transforms)
+    datalist = tag('datalist', base_transforms)
+    colgroup = tag('colgroup', base_transforms)
+    fieldset = tag('fieldset', base_transforms)
+    form = tag('form', base_transforms)
+    input_ = tag('input', base_transforms)
+    keygen = tag('keygen', base_transforms)
+    label = tag('label', base_transforms)
+    legend = tag('legend', base_transforms)
+    meter = tag('meter', base_transforms)
+    optgroup = tag('optgroup', base_transforms)
+    option = tag('option', base_transforms)
+    output = tag('output', base_transforms)
+    progress = tag('progress', base_transforms)
+    select = tag('select', base_transforms)
+    textarea = tag('textarea', base_transforms)
+
+    # Interactive
+    details = tag('details', base_transforms)
+    dialog = tag('dialog', base_transforms)
+    menu = tag('menu', base_transforms)
+    menuitem = tag('menuitem', base_transforms)
+    summary = tag('summary', base_transforms)
diff --git a/katla/styles.py b/katla/styles.py
new file mode 100644
index 0000000..1e6ef8a
--- /dev/null
+++ b/katla/styles.py
@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+"""
+    katla
+    :copyright: (c) 2016 by Yann Gravrand.
+    :license: BSD, see LICENSE for more details.
+"""
+
+
+def from_string(s):
+    """Returns a dictionary of styles from a styles string
+       :param s: Input string, eg. "display:none; text-align: right"
+       :return: A dictionary of styles {declaration: value}
+    """
+    declarations = [decl.strip().split(':') for decl in s.split(';')]
+    return {name.strip(): value.strip() for (name, value) in declarations}
+
+
+def to_string(d):
+    """Returns a string from a dictionary of styles
+       :param s: Styles dictionary, eg. {"display": "none", "text-align": "right"}
+       :return: A styles string
+    """
+    return '; '.join(['%s: %s' %
+                      (name, value) for name, value in d.items()])
diff --git a/katla/tag.py b/katla/tag.py
index e414840..709b5bb 100644
--- a/katla/tag.py
+++ b/katla/tag.py
@@ -4,15 +4,35 @@
     :copyright: (c) 2016 by Yann Gravrand.
     :license: BSD, see LICENSE for more details.
 """
-
 from lxml import etree
 
-from component import Component
+from .component import Component
+
+
+# Python 3 handling
+try:
+    unicode = unicode
+except NameError:
+    str, unicode, bytes, basestring = str, str, bytes, (str, bytes)
+else:
+    str, unicode, bytes, basestring = str, unicode, str, basestring
 
 
 class Tag(object):
+    """``Tag`` is the base class to render HTML tags"""
 
     def __init__(self, name, attrs_transforms):
+        """Init a tag.
+           :param name: Name of the tag to use in output
+           :param attrs_transforms: either:
+           - a dictionary of {``attribute_name``:``attribute_transform``},
+             each ``attribute_transform`` being a function:
+               :param name: Original attribute name
+               :param value: Original attribute value
+               :return: A (``name``, ``value``) tuple with the new attribute name and value
+           - a list of allowed attribute names
+           - None to apply no transform and disable restriction on attribute names
+        """
         self._name = name
         self._attrs_transforms = None
         if attrs_transforms is None:
@@ -44,7 +64,6 @@ def _extend(self, tree, children):
                 self._set_text(tree, child)
             # TODO comment case
             elif isinstance(child, Component):
-                print 'COMP CASE'
                 res = child.render(self._renderer)
                 if res is not None:
                     tree.append(res)
@@ -66,4 +85,5 @@ def _handle_attrs(self, attrs):
 
 
 def tag(name, attrs_transforms=None):
+    """Creates a ``Tag``, see ``Tag:__init__`` for documentation"""
     return Tag(name, attrs_transforms)
diff --git a/katla/attributes.py b/katla/transforms.py
similarity index 59%
rename from katla/attributes.py
rename to katla/transforms.py
index a8afbfe..9f038ae 100644
--- a/katla/attributes.py
+++ b/katla/transforms.py
@@ -3,15 +3,18 @@
     katla
     :copyright: (c) 2016 by Yann Gravrand.
     :license: BSD, see LICENSE for more details.
+
+    The ``transforms`` module defines usual transforms on attributes,
+    e.g. "className" --> "class"
 """
 
+from . import styles
+
 def className(name, val):
     return 'class', val
 
 
 def style(name, val):
     if isinstance(val, dict):
-        return (name, '; '.join(['%s: %s' %
-                                (attr_name, attr_value) for \
-                                attr_name, attr_value in val.items()]))
+        return name, styles.to_string(val)
     return name, val
diff --git a/setup.py b/setup.py
index 9f05303..76ae2d9 100644
--- a/setup.py
+++ b/setup.py
@@ -21,8 +21,7 @@
     packages=find_packages(),
     zip_safe=True,
     install_requires=(
-        'werkzeug',
         'lxml',
     ),
-    extras_require={'test': ('pytest',)}
+    extras_require={'test': ('pytest', 'werkzeug')}
 )
diff --git a/tests/test_component.py b/tests/test_component.py
index 1f5a16e..0784a2e 100644
--- a/tests/test_component.py
+++ b/tests/test_component.py
@@ -7,9 +7,9 @@
 
 import unittest
 
-from katla import attributes
+from katla import transforms
 from katla.component import Component
-from katla.renderer import BaseRenderer, base_attributes
+from katla.renderer import BaseRenderer, base_transforms
 from katla.tag import tag
 
 from .utils import render_tag
@@ -29,7 +29,7 @@ def render(self, r):
 
 class Renderer(BaseRenderer):
 
-    div = tag('div', base_attributes)
+    div = tag('div', base_transforms)
 
 
 class TestComponent(unittest.TestCase):
@@ -38,12 +38,12 @@ def test_simple(self):
         a = A()
         r = Renderer()
         self.assertEquals(render_tag(a.render(r)),
-                          '<div class="greetings">Hello World </div>',
+                          b'<div class="greetings">Hello World </div>',
                           'Simple component rendering')
 
     def test_composition(self):
         b = B()
         r = Renderer()
         self.assertEquals(render_tag(b.render(r)),
-                          '<div class="wrapper">Wrapped: <div class="greetings">Hello World </div><div class="greetings">Hello World </div></div>',
+                          b'<div class="wrapper">Wrapped: <div class="greetings">Hello World </div><div class="greetings">Hello World </div></div>',
                           'Simple component rendering')
diff --git a/tests/test_tag.py b/tests/test_tag.py
index 3d1b38c..b387854 100644
--- a/tests/test_tag.py
+++ b/tests/test_tag.py
@@ -7,7 +7,7 @@
 
 import unittest
 
-from katla import attributes
+from katla import styles, transforms
 from katla.tag import tag
 
 from .utils import render_tag
@@ -17,54 +17,55 @@ class TestTag(unittest.TestCase):
 
     div = tag('div')
     span = tag('span', ('alt',))
-    a = tag('a', {'className': attributes.className,
-                  'style': attributes.style})
+    a = tag('a', {'className': transforms.className,
+                  'style': transforms.style})
 
     def test_tags_and_text(self):
         d = self.div()
-        self.assertEquals(render_tag(d), '<div></div>',
+        self.assertEquals(render_tag(d), b'<div></div>',
                           'Empty tag')
 
         d = self.div('Hello')
-        self.assertEquals(render_tag(d), '<div>Hello</div>',
+        self.assertEquals(render_tag(d), b'<div>Hello</div>',
                           'Text only tag')
 
         d = self.div('Hello', ' ', 'World')
-        self.assertEquals(render_tag(d), '<div>Hello World</div>',
+        self.assertEquals(render_tag(d), b'<div>Hello World</div>',
                           'Tag with multiple concatenated texts')
 
         d = self.div('Hello', self.div('World'))
-        self.assertEquals(render_tag(d), '<div>Hello<div>World</div></div>',
+        self.assertEquals(render_tag(d), b'<div>Hello<div>World</div></div>',
                           'Child tag')
 
         d = self.div('Hello', self.span(' World'), ' ')
-        self.assertEquals(render_tag(d), '<div>Hello<span> World</span> </div>',
+        self.assertEquals(render_tag(d), b'<div>Hello<span> World</span> </div>',
                           'Child tag and texts')
 
     def test_tag_attributes(self):
         d = self.div('Hello', ' ', 'World', title='Hello', alt='Hello')
         self.assertEquals(render_tag(d),
-                          '<div alt="Hello" title="Hello">Hello World</div>',
+                          b'<div alt="Hello" title="Hello">Hello World</div>',
                           'Multiple attributes')
 
         d = self.div('Hello', self.span('World', alt='World'), ' ', title="Hello")
         self.assertEquals(render_tag(d),
-                          '<div title="Hello">Hello<span alt="World">World</span> </div>',
+                          b'<div title="Hello">Hello<span alt="World">World</span> </div>',
                           'Child with attributes')
 
         d = self.span('Hi', alt='World', title='World')
-        self.assertEquals(render_tag(d), '<span alt="World">Hi</span>',
+        self.assertEquals(render_tag(d), b'<span alt="World">Hi</span>',
                           'Forbidden attributes are cleared')
 
         d = self.a('Link', className='link')
         self.assertEquals(render_tag(d),
-                          '<a class="link">Link</a>',
+                          b'<a class="link">Link</a>',
                           'Attribute transform: className example')
 
-        d = self.a('Link', style={'display': 'none',
-                                  'text-decoration': 'underline'})
+        st = {'display': 'none',
+              'text-decoration': 'underline'}
+        d = self.a('Link', style=st)
         self.assertEquals(render_tag(d),
-                          '<a style="display: none; text-decoration: underline">Link</a>',
+                          b'<a style="%s">Link</a>' % styles.to_string(st),
                           'Attribute transform: style example')
 
 
diff --git a/tests/utils.py b/tests/utils.py
index 66a3ec9..c3896e4 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -15,5 +15,5 @@ def render_tag(tag):
                          pretty_print=False,
                          xml_declaration=False,
                          doctype=None)
-    print res
+    print(res)
     return res